Gene Kelly as Giovanni E. 'Johnny' Columbo

Teresa Celli as Isabella Gomboli

J. Carrol Naish as Louis Lorelli

Mario Siletti as Benny Danetta / Nino

Marc Lawrence as Caesar Xavier Serpi

Frank Puglia as Carlo Sabballera

Barry Kelley as Capt. Thompson

Carl Milletaire as George Allani / Tomasino

Eleonora von Mendelssohn as Maria Columbo

Peter Brocco as Roberto Columbo

Grazia Narciso as Mrs. Danetta

Mimi Aguglia as Mrs. Sabballera

Marc Krah as Lombardi