Aidman was born in Frankfort in Clinton County, Indiana. After graduating from Frankfort High School he served in the United States Navy from 1946-1948 attending officer’s training at DePauw University. He attended Indiana University in Indianapolis.  Among his many television credits, Aidman guest starred on NBC’s The Virginian (in the episode “The Devil’s Children”), and twice on the NBC western series, The Californians. He also appeared twice on David Janssen’s Richard Diamond, Private Detective. He portrayed a bounty hunter on the ABC’s western series, Black Saddle. He was cast in CBS’s fantasy drama, Twilight Zone in the episodes “And When the Sky Was Opened” and “Little Girl Lost”. About this time, he guest starred on five other western series: the ABC/Warner Brothers series, Colt .45; ABC’s The Rebel, starring Nick Adams; NBC’s Riverboat, as Frank Paxton in the episode “The Fight at New Canal”, with Darren McGavin as Captain Grey Holden, and The Americans, the story of family conflicts in the American Civil War starring Darryl Hickman and the successor series to Riverboat; CBS’s Trackdown, as Len Starbuck in “The Samaritan”, and CBS’s Johnny Ringo, as Jeffrey Blake in “The Stranger”.  Aidman played a scientist who turned into a werewolf in an episode of Voyage to the Bottom of the Sea (1966)

Aidman guest starred on the NBC children’s western, Fury with Peter Graves and Bobby Diamond and in episodes of the ABC/WB crime drama, Bourbon Street Beat, starring Andrew Duggan, and the syndicated aviation adventure series, Whirlybirds, starring Kenneth Tobey. He appeared from 1959 to 1960 in different roles in three episodes of the syndicated crime drama, U.S. Marshal, with John Bromfield. Aidman made a guest appearance on the CBS courtroom drama Perry Mason in 1960 as murderer Arthur Siddons in “The Case of the Gallant Grafter.”  In “Shadow of the Past” (October 7, 1961) of the NBC western series, The Tall Man, Aidman is cast as Ben Wiley, the father of Sue Wiley (Barbara Parkins), the latest girlfriend of Billy the Kid (Clu Gulager). Sheriff Pat Garrett (Barry Sullivan) recognizes Wiley as an informant who stopped Garrett from escaping from a Confederate prison during the American Civil War. Nancy Davis Reagan appears in this episode as Ben’s wife, Sarah.  Aidman was cast as George Ellsworth, an official with the United States Embassy in Warsaw, Poland, in the three-part 1963 episode, “Security Risk” of the CBS anthology series, GE True, hosted by Jack Webb. Ellsworth in 1960 is blackmailed through a romantic affair with a young woman named Erica into passing secret information to the communists at the height of the Cold War. He confessed his guilt despite the protection of diplomatic immunity. Karl Swenson and Parley Baer were also cast in this episode. He also played a sex education teacher in an episode of Slattery’s People, “Do The Ignorant Sleep in Pure White Sheets”?

In 1963, Aidman adapted Spoon River Anthology by poet Edgar Lee Masters into a theater production that is still performed.  He appeared on another NBC western series starring Barry Sullivan, The Road West in the 1966 episode “The Lean Years”.  Aidman guest starred on CBS’s The Wild Wild West in a recurring role for several episodes during the fourth season as Jeremy Pike, one of Jim West’s substitute sidekicks. (Ross Martin, who portrayed regular sidekick Artemus Gordon in the series, was recovering from illness.)  Aidman introduced the character Louis Willis (later known as Tom Willis), father-in-law to be of Lionel Jefferson, on an episode of CBS’s All In The Family. The character was played on the series The Jeffersons by Franklin Cover, who did a much different take on the character.  Aidman played the father of Elmer Dobkins in an episode of Little House On The Prairie and appeared in an episode of the 1974 police drama Nakia.  Aidman appeared in a memorable 1977 episode of M*A*S*H, “The Grim Reaper”, playing Colonel Bloodworth, a callous, sadistic commander who takes pleasure in predicting casualties and reducing his troops to statistics.  Later, Aidman served as the original narrator on the The Twilight Zone 1985-87 revival until he was replaced by Robin Ward.  His film roles were in Pork Chop Hill (1959), War Hunt (1962), Hour of the Gun (1967), Countdown (1968), Angel, Angel, Down We Go (1969), Tell Them Willie Boy Is Here (1969), Adam at 6 A.M. (1970), Kotch (1971), Dirty Little Billy (1972), Deliver Us from Evil (1973), Twilight’s Last Gleaming (1977), Zoot Suit (1981), Uncommon Valor (1983), and Innerspace (1987), the latter being one of his final acting appearances.  He died of cancer in Beverly Hills, California. He is interred at Westwood Village Memorial Park Cemetery in Los Angeles.