MacLeod was born Allan George See on February 28, 1981, in Mount Kisco, New York. After graduating from Ithaca College and a stint in the Air Force, he relocated to NYC, where he changed his name and sought work as an actor.
In 2019, MacLeod told his "Mary Tyler Moore" co-star Joyce Bulifant that he chose his professional last name to honor his cherished college teacher Beatrice MacLeod.
The newly rechristened MacLeod made his TV debut on a 1957 installment of "The Walter Winchell File," and his uncredited film debut the next year, in "The True Story of Lynn Stuart." A big break came with a credited part in the classic Susan Hayward drama "I Want to Live!," which led to his casting on the pilot for the TV series "Peter Gunn" that same year.
Though he made appearances in several other well-known films — among them "Compulsion" (1959) and "Operation Petticoat" (1959) — it was television where MacLeod would butter his bread, and eventually become an almost universally familiar face.
His first long-running hit was as Happy on the sitcom "McHale's Navy" (1962-1964), but instead of being happy about his success, MacLeod still felt he was not good enough. In 2013, he told "Extra" he began drinking and even attempted suicide during this period:
He has attributed this experience to his eventual conversion to Evangelical Protestantism, a major focus of his life in his later years.
After many more TV guest spots and film work in the '60s, MacLeod was cast as sardonic news writer Murray Slaughter on "Mary Tyler Moore," one of the top-rated and most critically acclaimed shows over the course of its 1970-1977 run. His performance garnered him two Golden Globe nominations.
Featuring MacLeod, Moore, Betty White, Valerie Harper, Cloris Leachman, Ed Asner, Ted Knight and Georgia Engel, the show is one of TV's most lasting success stories, and moved the medium forward with its adroit tackling of controversial themes using humor.
My heart is broken. Gavin was my brother, my partner in crime (and food) and my comic conspirator. I will see you in a bit Gavin. Tell the gang I will see them in a bit. Betty! It’s just you and me now. pic.twitter.com/se4fwh7G1G
When "MTM" ended, MacLeod went immediately into "The Love Boat," a very different kind of show — pure escapism and romance mixed with a rotating passenger list that featured everyone from previously retired Oscar winners to newcomers who would go on to fame. As the no-nonsense Captain Merrill Stubing, MacLeod anchored the series, which sailed for an astonishing 10 years, leaving some 250 episodes in its wake.
As part of his duties, MacLeod tap danced with Ginger Rogers and shared screen time with a who's who of TV and movie stars, including Lillian Gish, Olivia de Havilland, Debbie Reynolds, Helen Hayes, Ethel Merman, Ann Miller, Milton Berle, Phil Silvers, Florence Henderson, Eleanor Parker, Phyllis Diller, Barbara Rush, Jane Wyman, Jessica Walter, Carol Channing and many more.
Remarkably for a series that debuted over 40 years ago, MacLeod's was the first passing among the main cast, which also included Bernie Kopell, Lauren Tewes, Fred Grandy, Jill Whelan and Ted Lange.
MacLeod continued acting after the series docked in 1987, including appearances on "Oz" (2000), "The King of Queens" (2001 and 2002), "Touched by an Angel" (2003), "That '70s Show" (2006), and Disney Channel's "The Suite Life on Deck" (2009).
He made his final film, "The Secrets of Jonathan Sperry," in 2008, and his last TV guest spot in 2014, on "The Comeback Kids," but was a constant presence talking about the glory days of TV, his religious beliefs, and eulogizing other TV institutions.
Married to Joan Rootvik from 1954-1972, MacLeod wed Patti Kendig in 1974. Their union lasted until a 1982 divorce, but after both became religious, they were remarried and stayed together some 35 more years.
He is survived by his wife Patti and by four children.