[2] Ireland's other film roles include A Walk in the Sun (1945), Joan Of Arc (1948), Spartacus (1960), 55 Days at Peking (1963), The Fall of the Roman Empire (1964), The Adventurers (1970), and Farewell, My Lovely (1975).

[4] Ireland signed with 20th Century Fox and made his screen-debut as Private Windy, the thoughtful letter-writing GI, in the 1945 war film A Walk in the Sun, directed by Lewis Milestone.

Ireland played the lead in Open Secret (1948) for Eagle-Lion, then had a support role in Anthony Mann's classic noir, Raw Deal (1948).

Ireland had a vital support part in Howard Hawks' 1948 film Red River as the gunslinger Cherry Valance.

Ireland was nominated for an Oscar as Best Supporting Actor for his powerful performance as Jack Burden, the hard-boiled newspaper reporter who evolves from devotee to cynical denouncer of demagogue Willie Stark (Broderick Crawford) in All the King's Men (1949), making him the first Vancouver-born actor to receive an Academy Award nomination.

Ireland was featured as Bob Ford in the low budget I Shot Jesse James (1949) the first movie directed by Sam Fuller.

[6] Lippert Pictures gave him the lead in The Return of Jesse James (1950) and he appeared opposite his then-wife Joanne Dru in support parts in Vengeance Valley (1951) During McCarthyism in the early 50s, he successfully sued two television producers for breach of contract and slander, claiming that they reneged on roles promised to him due to his perceived political undesirability, including the lead in a TV series The Adventures of Ellery McQueen.

[4][7][8] Ireland had the leads in some low-budget films: The Basketball Fix (1951); The Scarf (1951); Little Big Horn (1951); The Bushwackers (1952); and Hannah Lee (1953) with his wife.

[9][10] He went to England to make The Good Die Young (1954) and supported his wife in Southwest Passage (1954) and Joan Crawford in Queen Bee (1955).

In 1959, Ireland appeared as Chris Slade, with Karl Swenson as Ansel Torgin, in the episode "The Fight Back" of the NBC Western series, Riverboat.

In a dispute over a wedding held on the Enterprise, a lynch-mob led by Fowler comes after series lead-character Grey Holden (Darren McGavin).

Ireland had a key role as the gladiator Crixus in the Stanley Kubrick 1960 spectacle Spartacus, co-starring with Kirk Douglas.

That year he starred as Winch in the Western series Rawhide episode "Incident of the Garden of Eden" and made Faces in the Dark (1960) in England.

From 1960 to 1962, he starred in the British television series The Cheaters, playing John Hunter, a claims investigator for an insurance company who tracked down cases of fraud.

He had a supporting part in 55 Days at Peking (1963) with Charlton Heston and was Ballomar in The Fall of the Roman Empire (1964), both films shot in Spain by producer Samuel Bronston.

In 1970, Ireland appeared as Kinroy in the TV Western The Men From Shiloh (rebranded name for The Virginian) in the episode titled "Jenny".

He did, however, also appear in big-budget fare such as The Adventurers (1970), also as a police lieutenant in the Robert Mitchum private-eye story Farewell, My Lovely (1975).

He starred in Thunder Run (1986), an American action-thriller film directed by Gary Hudson and co-starring Forrest Tucker.

Occasionally Ireland's name was mentioned in tabloids of the times, in connection with much younger starlets, including Natalie Wood, Barbara Payton, and Sue Lyon.

From 1949 to 1957, he was married to actress Joanne Dru (whose younger brother, entertainer Peter Marshall, was originally best known for his comedy act with Ireland's half-brother Tommy Noonan).