Ladd's professional career in Hollywood began in 1957 with a supporting role in a film starring his father titled The Big Land. As a result of that film's success, Samuel Goldwyn Jr offered him a role as a mute in the 1958 movie The Proud Rebel, once again playing opposite his father and co-starring Olivia de Havilland. For this role, Ladd won a Golden Globe award as the "Best Newcomer of 1958" as well as a special award for "Best Juvenile Actor", and received a Best Supporting Actor nomination. He was also included in Film Daily's Filmdom's Famous Five critic's award.

Ladd followed this success with a series of films including The Sad Horse (1959), A Dog of Flanders (1960), Raymie (also 1960) and Misty (1961), as well as appearing in numerous television shows including Bonanza, Zane Grey Theatre, and Shirley Temple's Story Book Theatre (as Tom Sawyer). Ladd was again included in Film Daily's Filmdom's Famous Five in 1961 for A Dog of Flanders. Ladd's other feature film credits include RPM (1970), The Day of the Locust (1975), The Treasure of Jamaica Reef (1975), Jonathan Livingston Seagull (1977) and The Wild Geese (1978).

Ladd was born in Los Angeles, California, the son of Alan Ladd, an actor, and Sue Carol, an Actress and talent agent. His siblings are Alana Ladd Jackson, Carol Lee Ladd, and Alan Ladd Jr. He attended Harvard-Westlake School in Los Angeles and, following the death of his father in 1964, graduated from the University of Southern California where he earned a Bachelor of Science degree while also fulfilling his military obligations in the Air Force Reserves.

In 1972, Ladd met Actress Cheryl Stoppelmoor, with whom he later had a daughter, Jordan. In 1977, Cheryl Ladd replaced Farrah Fawcett on Charlie's Angels. David began to turn his attention toward producing. His first productions were for ABC and included specials and movies of the week, most notably When She Was Bad (1979) starring Cheryl and Robert Urich. David and Cheryl Ladd divorced in 1980. In 1982, Ladd married Actress Dey Young (the younger sister of Actress Leigh Taylor-Young), with whom he has another daughter, Shane Ladd.

In 1982, Ladd began working at Columbia Pictures as a creative executive. Shortly thereafter, his brother-in–law, John Veitch, stepped down as President of Columbia and asked Ladd to join him in establishing a new production company based at Columbia.

Ladd's first solo producing credit came in the motion picture The Serpent and the Rainbow (1988), based on Wade Davis' book of the same name. The film was quite successful, and he was subsequently asked to join his half-brother Alan Ladd Jr in forming Pathe Films in 1988. The duo produced several films before acquiring the venerable Metro-Goldwyn-Mayer (MGM).

Ladd became a senior production executive at MGM and was part of the key team responsible for the resurgence of the studio (1989–1997). He was responsible for a variety of films, including the smash hit Get Shorty (1995).

Ladd left MGM as an executive in 1998, and signed a deal to produce movies for them. His first production was a re-imagining of the hit TV series The Mod Squad, in which he shared an Executive Producer credit with Aaron Spelling, with whom he had first collaborated on The Zane Grey Theatre in 1961.

During this period, MGM changed hands twice, but Ladd was able to continue his productions. He found a manuscript written by John Katzenbach and developed it as a screenplay for the 2002 film, Hart's War, directed by Gregory Hoblit and starring Bruce Willis, Colin Farrell and Terrence Howard. Ladd followed this up with the 2003 comedy A Guy Thing.

Ladd spent a portion of 2007 teaching film production at the Savannah College of Art and Design. He is a member of the Producers Guild of America, the Academy of Motion Picture Arts and Sciences, and an emeritus member of the Screen Actors Guild.

Shortly thereafter, MGM was sold and Ladd left the company as an independent. He is currently developing projects for Fox, Universal and Paramount, as well as projects for the independent film market-place. In 2008, he helped shepherd Kevin Sheridan's Leaving Barstow, which won several awards on the film festival circuit.