Who is Radar O'Reilly in M*A*S*H?

Show

M*A*S*H

Played by

Gary Burghoff

First episode

“Pilot”Season 1, Episode 1, aired September 17, 1972

Role

Main cast

Network

CBS

Occupation

Company clerk, 4077th MASH

Show run

1972 to 1983

Also known as

Radar, Walter O'Reilly, Walter Eugene O'Reilly, Corporal O'Reilly

Corporal Walter "Radar" O'Reilly is the 4077th's company clerk, an innocent farm kid with an uncanny knack for knowing what is coming. Gary Burghoff played him in the 1970 film and then for more than seven seasons of M*A*S*H.

On M*A*S*H, Radar O'Reilly's story runs through Sherman Potter (Father Figure), Hawkeye Pierce (Friend), Maxwell Klinger (Successor as Clerk), B.J. Hunnicutt (Friend), and Frank Burns (Officer).

Who is Radar O'Reilly?

Radar is a young corporal from Ottumwa, Iowa, who joined the Army straight out of high school. As company clerk he handles the paperwork, the phones, the PA system, and the radio, and he quietly keeps the whole unit running. He earned his nickname by hearing incoming helicopters long before anyone else and by finishing his commander's sentences before they are spoken.

He looks up to his commanders as father figures, first Henry Blake and then Sherman Potter, having lost his own father young. The doctors look out for him in return, and few things move Hawkeye more than seeing Radar hurt.

Personality and comedy

In the earliest episodes Radar is a sly operator who runs small scams around camp, much like his film version. The writers and Burghoff soon reshaped him into a sweet, naive farm boy who sleeps with a teddy bear, drinks grape Nehi, reads comic books, and is hopelessly awkward around women.

His comedy comes from that innocence paired with real competence. He mangles nearly every bugle call he attempts, but he can forge a requisition, work the phones, or anticipate an order better than anyone in Korea.

Key storylines

Radar has a soft spot for animals and for Colonel Potter. In "Dear Mildred" he gives the new commander a rescued horse, cementing their bond, and in "Lt. Radar O'Reilly" he is briefly made an officer before realizing he would rather be a corporal. He is wounded during a trip to Seoul in "Fallen Idol," and Hawkeye blames himself.

In the two-part "Good Bye, Radar" early in season eight, Radar learns his Uncle Ed has died and is offered a hardship discharge to help his mother on the farm. He hesitates, worried the unit needs him more than his family does, and goes home only once he is satisfied that Klinger can take over. He leaves his teddy bear on Hawkeye's bunk, and the bear later goes into the camp's time capsule.

Behind the scenes and legacy

Gary Burghoff was the only regular to play the same character in both the film and the TV series, and he chose the first name Walter himself. He won an Emmy for the role in 1977. Worn down by the schedule, he cut back his appearances, finished season seven, and returned for a two-part farewell early in season eight.

Burghoff returned as Radar in two episodes of AfterMASH and in W*A*L*T*E*R, an unsold 1984 pilot that made Radar a St. Louis police officer. The teddy bear and the grape Nehi remain instantly recognizable symbols of the show.

Radar O'Reilly: frequently asked questions

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