Murder on the Blackboard

Edna May Oliver

Hildegarde Withers

James Gleason

Inspector Oscar Piper

Bruce Cabot

Addison

Gertrude Michael

Jane Davis

Regis Toomey

Detective Smiley North

Edgar Kennedy

Detective Donahue

Tully Marshall

Mr. MacFarland

Jackie Searl

Leland Stanford Jones

Frederick Vogeding

Otto Schweitzer, the Janitor (as Fredrik Vogeding)

Barbara Fritchie

Louise Halloran

Gustav von Seyffertitz

Dr. Max Von Immen

Tom Herbert

Detective McTeague

Jed Prouty

Dr. Levine

Wade Boteler

Bearded diner (Uncredited)

Tommy Bupp

School boy (uncredited)