Herb Davis, 56, a veteran Washington radio and television personality and Channel 20's "Mr. Movie," died of cardiac arrest early Sunday at George Washington University Hospital.

He had collaped Saturday night while performing in A. Beethoven Nightcap," a show at the West End Theatre.

Mr. Davis had been on the staff of WDCA-TV since the station went on the air in 1966. He was "Mr. Money" on the daily game show "Dialing for Dollars." At the time of his death, he was the host of the daily "Prize Movie" show and also was the station's public affairs director. In the latter capacity, he was host of the weekly "Metropolitan Washington in Action" and "Challenge" programs.

Mr. Davis was born in Mt. Vernon, N.Y. He graduated from New York University and came to Washington from Syracuse, N.y/., about 1951. He worked fro radio stations WINX, WOL, WEAM, WAVA, WEEL and Wezr/ before joining Channel 20.

He was a member of Temple Beth-El in Alexandria.

Survivors include his wife, Alice, of the home in Falls Church, and a daughter, Judith Lynne, also of Falls Church.

The family suggests that expressions fo sympathy be in the form of contributions to the Heart Fund.