He was born Alphonso Joseph D'Abruzzo on January 28, 1936 in New York City. He attended Archbishop Stepinac High School in White Plains, New York.
In 1956, he received his Bachelor of Arts degree in English from Fordham College of Fordham University in the Bronx, where he was a student staff member of its FM radio station,
During Alda's young junior year, he studied in Paris, acted in a play in Rome, and performed with his father on television in Amsterdam. In college, he was a member of the ROTC, and after graduation, he served for a year at Fort Benning, and then six months in the U.S. Army Reserve.
His most famous role was Hawkeye Pierce, a surgeon in a MASH hospital during the Korean War, in the TV series M*A*S*H, an adaptation of the film of the same name. The show ran for 11 years and Alda appeared in all 251 episodes. His role as Hawkeye Pierce earned him six Emmy Awards and six Golden Globe Awards.
After M*A*S*H, Alda used his fame to speak on political issues and bring major support to movements such as women's rights and the feminist movement, describing himself as a liberal and progressive activist.
In acting, Alda appeared frequently alongside Woody Allen in multiple films, guest starred on ER, starred in the political satire film Canadian Bacon and appearing as a regular cast member on The West Wing, where he played Republican US Senator Arnold Vinick. He also co-starred alongside Leonardo DiCaprio in The Aviator.
Throughout his career, Alda has been nominated 31 times for Emmy Awards, twice for a Tony Award an once for an Academy Award. He has won six Emmy Awards, six Golden Globes, seven People's Choice Awards, three Directors Guild of America awards, a Drama Desk Award and has been inducted into the Television Hall of Fame.