You're Only Young Twice!

Duncan Macrae

Professor "Haywire" Hayman

Joseph Tomelty

Connell O'Grady aka Dan McEntee

Patrick Barr

Sir Archibald Asher

Charles Hawtrey

Adolphus Hayman

Diane Hart

Ada Shore

Robert Urquhart

Sheltie

Edward Lexy

Lord Carshennie

Jacqueline Mackenzie

Nellie Kelly

Eric Woodburn

The Bedellus

Molly Urquhart

Lady Duffy

Ronnie Corbett

Maither

Reginald Beckwith

Radio reporter

Russell Waters

Professor Baikie

Wendy Noel

Miss Mear

Roddy McMillan

Milligan

Alastair Hunter

Desk Sergeant

Andrew Downie

Student

Archie Duncan

Police Constable