Giovanni E. 'Johnny' Columbo
Louis Lorelli
Isabella Gomboli
Caesar Xavier Serpi
Carlo Sabballera
Police Capt. Thompson
Benny Danetta / Nino
George Allani / Tomasino
Roberto Columbo
Maria Columbo (as Eleonora Mendelssohn)
Mrs. Danetta
Moriani
Judge
Prosecutor
Mrs. Sabballera
Bettini
Pietro Riago
Lombardi
Rudi Gomboli
Mary the Shamrock
Customer (uncredited)
Mr. Larti (uncredited)
Mrs. Larti (uncredited)
Courtroom Spectator (uncredited)
Footpad (uncredited)
Townsman (uncredited)
Defense Attorney (uncredited)
Policeman (uncredited)
Enrico - Naples Bus Boy (uncredited)
Translator (uncredited)
Saturnine (uncredited)
Laborer (uncredited)
Passerby on Sidewalk (uncredited)
Tourist (uncredited)
Juror (uncredited)
Don Giuseppe (uncredited)
Alfredo (uncredited)
Man on Boat (uncredited)
Manageress (uncredited)
Waiter (uncredited)
Minor Role (uncredited)
Official (uncredited)
Businessman (uncredited)
Officer of Boat (uncredited)
Signora Bernadoni (uncredited)
Assistant Consul (uncredited)
Police Officer (uncredited)
Sestini (uncredited)
Italian Street Merchant (uncredited)
Townswoman (uncredited)
Restaurant Patron (uncredited)
Rat Type (uncredited)
Fire Chief (uncredited)
Johnny Columbo, Age 14 (uncredited)
Hokey-Pokey Man (uncredited)
Headwaiter (uncredited)
Court Bailiff (uncredited)
Hurdy-Gurdy Man (uncredited)
Clerk (uncredited)
Editor (uncredited)
Sexton (uncredited)
Semi-Moron (uncredited)
Hunchback (uncredited)
Bailiff (uncredited)
Man on the Street (uncredited)
Signora Di Palma (uncredited)
Handwriting Expert (uncredited)
Cartman (uncredited)
Mr. Abanase (uncredited)
Signor Taricco (uncredited)