Named after actor Ronald Colman, Walken was born Ronald Walken on March 31, 1943 in Astoria, Queens, New York City. He is the son of Rosalie (née Russell; May 16, 1907 – March 26, 2010), a Scottish emigrant from Glasgow, and Paul Wälken (October 5, 1903 – February 23, 2001), who came to the U.S. from Horst, Germany in 1928. His father owned and operated Walken's Bakery in Astoria. Walken was raised a Methodist.

Influenced by their mother's own dreams of stardom, he and his brothers, Kenneth and Glenn, were child actors on television in the 1950s. At age 15, when a girlfriend showed him a magazine photo of Elvis, Walken said, "This guy looked like a Greek god. Then I saw him on television. I loved everything about him." He changed his hairstyle to imitate Elvis and hasn't changed it since (Robert Schnakenberg (2008). "Christopher Walken A to Z".). As a teenager, he worked as a lion tamer in a circus. Walken went to Hofstra University, but dropped out after one year, having gotten the role of Clayton Dutch Miller in an Off-Broadway revival of Best Foot Forward, co-starring with Liza Minnelli, who played Ethel Hofflinger. Walken initially trained as a Dancer in music theatre at the Washington Dance Studio before moving on to dramatic roles in theatre and then film.

As a child, Walken appeared on screen as an extra in numerous anthology series and variety shows during the Golden Age of Television. After appearing in a Sketch with Martin and Lewis on The Colgate Comedy Hour, Walken decided to become an actor. He landed a regular role in the 1953 television show The Wonderful John Acton as the show's narrator. During this time, he was credited as Ronnie Walken.

Over the next two years, he appeared frequently on television (landing a role in the experimental film Me and My Brother) and had a thriving career in theatre. From 1954 to 1956, Walken and his brother Glenn originated the role of Michael Bauer on the soap opera The Guiding Light. In 1963, he appeared as a character named Chris in an episode of Naked City, starring Paul Burke. In 1966, Walken played the role of King Philip of France in the Broadway premiere of The Lion in Winter. In 1969, Walken guest-starred in Hawaii Five-O as Navy SP Walt Kramer.

In 1964, he changed his first name to Christopher at the suggestion of Monique van Vooren, who had a nightclub act in which Walken was a Dancer and who believed the name suited him better than Ronnie (a pet form of his given name, Ronald), which he was credited as until then. He prefers to be known informally as Chris instead of Christopher.

Walken married Georgianne Walken (née Thon), a casting Director, in 1969. She is most notable for The Sopranos. The couple have no children. Walken has stated in interviews that having no children is one of the reasons he has had such a prolific film career. The Walkens have a cat named Bowtie and their previous cat was named Flapjack. The couple lives in Westport, Connecticut and they also have a vacation home on Block Island, Rhode Island.

Walken made his feature film debut with a small role opposite Sean Connery in Sidney Lumet's The Anderson Tapes. In 1972's The Mind Snatchers a.k.a. The Happiness Cage, Walken played his first starring role. In this science fiction film, which deals with mind control and normalization, he plays a sociopathic U.S. soldier stationed in Germany.

Paul Mazursky's 1976 film Next Stop, Greenwich Village had Walken, under the name "Chris Walken", playing fictional poet and ladies' man Robert Fulmer. In Woody Allen's 1977 film Annie Hall, Walken played the homicidal and borderline crazy brother of Annie Hall (Diane Keaton). Also in 1977, Walken had a minor role as Eli Wallach's partner in The Sentinel. In 1978, he appeared in Shoot the Sun Down, a western filmed in 1976 that costarred Margot Kidder. Along with Nick Nolte and Burt Reynolds, Walken was considered by George Lucas for the part of Han Solo in Star Wars; the part ultimately went to Harrison Ford.

In 1977, Walken also starred in an episode of Kojak as Ben Wiley, a robber.

Walken won an Academy Award for Best Supporting Actor in Michael Cimino's 1978 film The Deer Hunter. He plays a young Pennsylvania steelworker who is emotionally destroyed by the Vietnam War. To help achieve his character's gaunt appearance before the third act, Walken consumed only bananas, water, and rice for a week.

Walken's first film of the 1980s was the controversial Heaven's Gate, directed by Cimino of Deer Hunter fame. Walken also starred in the 1981 action adventure The Dogs of War, directed by John Irvin. He surprised many critics and filmgoers with his intricate tap-dancing striptease in Herbert Ross's musical Pennies from Heaven (1981). In 1982, he played a socially awkward but gifted theater actor in the film adaptation of Kurt Vonnegut Jr.'s short story Who Am I This Time? opposite Susan Sarandon. Walken then played schoolteacher-turned-psychic Johnny Smith in David Cronenberg's 1983 adaptation of Stephen King's The Dead Zone. That same year, Walken also starred in Brainstorm alongside Natalie Wood and (in a minor role) his wife, Georgianne.

Walken was one of the last persons to see Natalie Wood alive before her drowning on November 29, 1981, near Santa Catalina Island, California, while on a Thanksgiving weekend boating trip. In 2011, Walken hired a Lawyer when authorities reopened the Wood case, while the LAPD said, "Walken is not a suspect." The case was closed and termed an accidental death until June 2012, when the investigation was reopened and the cause of death was changed to "undetermined". Authorities stated that Walken is not a suspect.

Walken spoofed his starring role from The Dead Zone (1983) in a Sketch titled "Ed Glosser: Trivial Psychic" (1992). In the film Walken's character can predict deaths and catastrophes, while Glosser can accurately predict meaningless, trivial Future but with the same emotional intensity as in the film: "You're going to get an ice cream headache. It's going to hurt real bad, right here, [touches forehead] for eight, nine seconds.").

In 1985, Walken played a James Bond villain, Max Zorin, in A View to a Kill, Roger Moore's last appearance as Bond. Walken dyed his hair blond to befit Zorin's origins as a Nazi experiment.

At Close Range (1986) starred Walken as Brad Whitewood, a rural Pennsylvania crime boss who tries to bring his two sons into his empire; his character was mostly based on Criminal Bruce Johnston.

In 1988, Christopher Walken played a memorable role as Sgt. Merwin J. Toomey in Neil Simon's Biloxi Blues which was directed by Mike Nichols, and the role of Federal Agent Kyril Montana in Milagro Beanfield War. He also played the leading role of Whitley Strieber in 1989's Communion, an autobiographical film written by Strieber based on his claims that he and his friends were subject to visitations by unknown, other-worldly entities variously identified as possibly "aliens" or, simply, as "visitors". In 1989, he played the lead role of "Puss" in the Cannon theatre group's musical version of Puss in Boots.

Walken also starred in two music videos in the 1990s. His first video role was as the Angel of Death in Madonna's 1993 "Bad Girl". The second appearance was in Skid Row's "Breakin' Down" video.

Later in 1994, Walken starred in A Business Affair, a rare leading role for him in a romantic comedy. Walken manages to once again feature his trademark dancing scene as he performs the tango. In 1995, he appeared in Things to Do in Denver When You're Dead, Wild Side, The Prophecy and the modern vampire flick The Addiction, which was his second collaboration with Director Abel Ferrara and Writer Nicholas St. John. He also appeared in Nick of Time, which also stars Johnny Depp, and an art house film by David Salle, Search and Destroy. In 1995, Walken acted in "Him," a first play written by Walken about his idol Elvis in the afterlife featured in the New York Shakespeare Festival. (R. Tantich, "Plays and Players," New York, 1995)

In the 1996 film Last Man Standing, Walken plays a sadistic gangster named Hickey. That year, he played a prominent role in the video game Ripper, portraying Detective Vince Magnotta. Ripper made extensive use of real-time recorded scenes and a wide cast of celebrities in an interactive movie. In 1996 Walken also appeared in the Italian film Celluloide as US Officer Rod Geiger and played the role of Ray in the Abel Ferrara crime-drama film The Funeral. In 1997, Walken starred in the comedy films Touch and Excess Baggage and had a minor role in the film MouseHunt. He also appeared in the drama/thriller film Suicide Kings, which was also filled with suspense and humor.

In 1998, Walken played an influential gay New York theater critic in John Turturro's film Illuminata. The same year he voiced Colonel/General Cutter in the computer-animated Antz movie.

In 1999, Walken played Calvin Webber in the romantic comedy Blast from the Past. Webber is a brilliant but eccentric Caltech nuclear Physicist whose fears of a nuclear war lead him to build an enormous fallout shelter beneath his suburban home. The same year, he appeared as the Headless Horseman in Tim Burton's Sleepy Hollow, starring Johnny Depp and Christina Ricci. He also appeared in Kiss Toledo Goodbye with Michael Rapaport and Nancy Allen.

In 2000, Walken was cast as the lead, along with Blair Brown, in James Joyce's The Dead on Broadway. A "play with music", The Dead featured music by Shaun Davey, conducted by Charles Prince, with music coordination and percussion by Tom Partington. James Joyce's The Dead won a Tony Award that year for Best Book for a Musical.

Also in 2001, Walken played Lieutenant Macduff in Scotland, Pa, Billy Morissette's loose film adaptation of Shakespeare's Macbeth.

In 2002 Walken played Mike in the film Poolhall Junkies and played Frank Abagnale, Sr. in Catch Me If You Can, which is inspired by the story of Frank Abagnale, Jr., a con Artist who passed himself off as several identities and forged millions of dollars' worth of checks. His portrayal earned him an Academy Award nomination for Best Supporting Actor. Walken also had a part in the 2003 action comedy film The Rundown, starring Dwayne "The Rock" Johnson and Seann william Scott, in which he plays a ruthless despot. He was nominated for a Razzie (Worst Supporting Actor) in 2002's The Country Bears and in two 2003 movies, Gigli and Kangaroo Jack. Walken also starred in Barry Levinson's Envy, in which he plays J-Man, a crazy guy who helps Ben Stiller's character, and in his starring role in 2004's Around the Bend he again has a dancing scene as he portrays an absentee father who has fled prison to reunite with his father, his son, and the grandson he never knew before dying. Walken played the role of Paul Rayburn in 2004's Man on Fire, where, when speaking about the imminent destructive actions of John Creasy (Denzel Washington), his character states: "A man can be an Artist... in anything, food, whatever. It depends on how good he is at it. Creasy's art is death. He's about to paint his masterpiece."

Until 2003, Walken had a recurring SNL Sketch called "The Continental", in which Walken played a "suave ladies' man" who in reality cannot do anything to keep a woman (a neighbor in his apartment building) from giving him the cold shoulder. Though he is outwardly chivalrous, his more perverted tendencies inevitably drive away his date over his pleading objections. For instance, he invites the woman to wash up in his bathroom; once she is inside, it becomes obvious that the bathroom mirror is a two-way mirror when he is seen lighting up a cigarette. In "The Continental", only the hand of his neighbor is ever seen; the camera always shows her point of view.

Also in 2004, Walken played Mike in the film The Stepford Wives.

In 2005, he played Mark Heiss in the film Domino and the role of Secretary Cleary in the film Wedding Crashers.

Walken became the subject of a hoax controversy in 2006, when a fake website started in August of that year by members of Internet forum Genmay.com announced that he was running for President of the United States. Some believed it was authentic, until Walken's publicist dismissed the claims. When asked about the hoax in a September 2006 interview with Conan O'Brien, Walken said he was amused; and when asked to come up with a campaign slogan, he replied, "What the Heck" and "No More Zoos!"

The April 5, 2008 Saturday Night Live show was the first time an episode hosted by Walken did not have a "Continental" Sketch or a monologue in which he sang and danced. This episode, however, did include one Sketch titled "Meet the Family", which spoofs many of Walken's idiosyncrasies. The Sketch depicts a fictional Walken family reunion, where all of Christopher's relatives have his mannerisms and speech patterns, and sport his trademark pompadour hairstyle. In order of appearance, the other Walkens are Christopher's cousin Stanley (Bill Hader); Stanley's brother John (Jason Sudeikis); John's son Scott (Andy Samberg) and daughter Maxine (Amy Poehler) (who carries a doll that also has a pompadour); Nathan (Fred Armisen), a gay relative for whom "flamboyance" means dressing all in black and running his finger around the rim of a cosmo glass; Uncle Richard (Darrell Hammond) and Aunt Martha (Kristen Wiig), who think that The Deer Hunter was hilarious, and who are hosts of a Nigerian foreign exchange student named Oleki (Kenan Thompson). When he came to live with them, Oleki—who has absorbed all of the Walken Family traits—could not speak any English. But now (he says) he "talks like a normal teenaged American boy". The biggest laugh of the Sketch occurs when Christopher expresses his sympathies for Scott's teenaged attitude: "I appreciate your situation. For a Walken, adolescence is a difficult time. You feel like you're the only normal person in a school full of nutjobs." Scott's response: "Wow! It's like you're lookin' right into my noggin!" (Will Forte also appears as a waiter at the beginning of the Sketch, but does not do a Walken impression.)

The film The Maiden Heist, a comedy co-starring Morgan Freeman, william H. Macy and Walken about security guards in an art museum, debuted at the Edinburgh International Film Festival on June 25, 2009.

Described as "diverse and eccentric" and "one of the most respected actors of his generation", Walken has long established a cult following among film fans. He's known for his versatility and named as one of Empire magazine's "Top 100 Movie Stars of All Time". Once dubbed as a "cultural phenomenon", he has portrayed several iconic movie characters including Johnny Smith in The Dead Zone, Max Shreck in Batman Returns and Max Zorin in A View to a Kill and was also considered for the role of Han Solo in Star Wars films. His Oscar-winning performance in The Deer Hunter ranked as 88th greatest movie performance of all time by Premiere magazine and his performance in Pennies from Heaven was made into Entertainment Weekly's list of the "100 Greatest Performances that should have won Oscars but didn't". Sometimes regarded as "one of the kings of cameos", Walken has made several notable cameo appearances or appeared in a single but popular scene of films including Captain Koons in Pulp Fiction, Duane in Annie Hall, Hessian Horseman in Sleepy Hollow, and Don Vincenzo in True Romance's popular "Sicilian scene" which was described by Quentin Tarantino as one of the proudest moments in his career.

In December 2012, Walken was selected as a "GQ" Man of the Year. ("Gentlemen's Quarterly." April 2018. p. 24)

In 2013, Walken became the protagonist in the campaign "Made From Cool" by Jack & Jones. In 2014, he appeared in Turks & Caicos. Walken appears as Gyp DeCarlo in the 2014 film Jersey Boys.

In 2014, Walken played Captain Hook in the NBC production Peter Pan Live!

In 2015, Walken starred in the film When I Live My Life Over Again and played the role of Clem for the second time in the David Spade comedy Joe Dirt 2: Beautiful Loser.

In 2016, he voiced King Louie in the CGI-live action remake of Disney's The Jungle Book. He also recorded a cover of Louie's song I Wan'na Be like You, which he sings in the film as well as on the Soundtrack.