Murder on the Blackboard

Edna May Oliver

— Hildegarde Withers

James Gleason

— Police Insp. Oscar Piper

Bruce Cabot

— Stevens

Gertrude Michael

— Jane Davis

Regis Toomey

— Detective Smiley North

Edgar Kennedy

— Detective Donahue

Tully Marshall

— MacFarland

Jackie Searl

— Leland

Frederick Vogeding

— Otto (as Fredrik Vogeding)

Barbara Fritchie

— Louise

Gustav von Seyffertitz

— Dr. Von Immen

Tom Herbert

— Detective McTeague

Jed Prouty

— Dr. Levine

Wade Boteler

— Bearded Diner (Uncredited)

Tommy Bupp

— School Boy (uncredited)

Frank Mills

— Diner Counterman (uncredited)

Monte Vandergrift

— Policeman (uncredited)