On the south bank of the River Thames in London, near where the modern recreation of Shakespeare's Globe stands today, is a plaque that reads: "In Thanksgiving for Sam Wanamaker, Actor, Director, Producer, 1919–1993, whose vision rebuilt Shakespeare's Globe Theatre on Bankside in this parish". There is a blue plaque on the river-side wall of the theatre, and the site's Jacobean indoor theatre, opened in January 2014, is named the Sam Wanamaker Playhouse after him.

He trained at the Goodman Theatre in Chicago and began working with summer stock theatre companies in Chicago and northern Wisconsin, where he helped build the stage of the Peninsula Players Theatre in 1937.

In 1940, Wanamaker married Canadian Actress Charlotte Holland.

Wanamaker began his acting career in traveling shows and later worked on Broadway. In 1942 he starred with Ingrid Bergman in the play, Joan of Lorraine, and directed Two Gentlemen from Athens the following year.

In 1943, Wanamaker was part of the cast of the play Counterattack at the National Theatre, Washington, D.C.. During the play, he became enamored of the ideals of liberal politics. He attended Drake University prior to serving in the U.S. Army between 1943 and 1946, during the Second World War. In 1947, he returned to civilian life as an actor and Director.

In 1951, Wanamaker made a speech welcoming the return of two of the Hollywood Ten. In 1952, at the height of the McCarthy "Red Scare" period, despite his distinguished Service in the Army during World War II, Wanamaker, who was then acting in the UK, learned that his early years as a sympathizer of liberalism could be used to have him blacklisted in Hollywood. He consequently decided to remain in England, where he reestablished his career as a stage and film actor, along with becoming a Director and Producer. He explains:

In 1952 he made his debut as both actor and Director in London in Clifford Odets' Winter Journey. The play, which co-starred Michael Redgrave, was considered "sensational" by critics, He later appeared in other plays, including The Big Knife, The Shrike, The Rainmaker, and A Hatful of Rain. In 1956 he directed a play by Bertolt Brecht, The Threepenny Opera.

In 1957, he was appointed Director of the neglected New Shakespeare Theatre, in Liverpool. He brought a number of notable productions to the theatre, such as A View From the Bridge, Cat on a Hot Tin Roof, The Rose Tattoo and Bus Stop. It was also transformed into a lively arts centre as a result of including other cultural attractions, such as films, lectures, jazz concerts and art exhibits.

As a result of all his various activities, Wanamaker became London's "favourite American actor and Director," notes The Guardian. In 1959, he joined the Shakespeare Memorial Theatre company at Stratford-upon-Avon, playing Iago to Paul Robeson's Othello in Tony Richardson's production that year. In the 1960s and 1970s, he produced or directed several works at venues including the Royal Opera House, Covent Garden, and directed the Shakespeare Birthday Celebrations in 1974.

In 1970 Wanamaker's career took a dramatic turn after he was annoyed by the fact that while a number of Globe Theatres had been replicated in America, the actual site of the original in London was marked by only a plaque on a nearby brewery. He then made it his single-minded goal to restore an exact replica of the Globe to feature plays and a museum.

As a Director and actor, he worked in both films and television, with roles in The Spiral Staircase (1974), Private Benjamin (1980), Superman IV: The Quest for Peace (1987), and Baby Boom (1987). He also directed stage productions, including the world premiere production of Michael Tippett's opera The Ice Break. In 1980, he directed Giuseppe Verdi's opera "Aida" starring Luciano Pavarotti at San Francisco Opera (now broadcast version released as DVD). He was also featured as the widowed and very ruthless department store owner Simon Berrenger on the short-lived drama Berrenger's in 1985.

For his work in reconstructing the Globe Theatre, Wanamaker, in July 1993, was made an honorary Commander of the Order of the British Empire (CBE). He was also honoured with the Benjamin Franklin Medal by the Royal Society of Arts in recognition of his contribution to theatre.

Wanamaker died of prostate cancer in London in 1993, aged 74, before his dream could be finalized, and prior to the grand opening of the Globe by Queen Elizabeth II on 12 June 1997. He was survived by three daughters, Abby, Zoë, and Jessica.

When multi-Tony Award-winning British actor Mark Rylance accepted his third Tony on stage in New York City during the televised ceremonies on June 8, 2014, he did so with a note of thanks to Wanamaker.

Though, as in the late 16th and 17th centuries, the 20th century Royal family were more or less supportive, British officialdom was far less so, since they wanted to develop the site for new high-rise housing and commercial use. English Heritage, which controlled the site, refused to give Wanamaker the precise dimensions of the original Globe.