Don Ameche as Alexander Graham Bell

Loretta Young as Mrs. Mabel Hubbard Bell

Henry Fonda as Thomas Watson

Charles Coburn as Gardner Hubbard

Gene Lockhart as Thomas Sanders

Spring Byington as Mrs. Hubbard

Sally Blane as Gertrude Hubbard

Polly Ann Young as Grace Hubbard

Georgiana Young as Berta Hubbard

Bobs Watson as George Sanders

Russell Hicks as Mr. Barrows

Paul Stanton as Chauncey Smith

Jonathan Hale as President of Western Union

Harry Davenport as Judge Rider

Beryl Mercer as Queen Victoria

Elizabeth Patterson as Mrs. MacGregor

Charles Trowbridge as George Pollard

Jan Duggan as Mrs. Winthrop

Claire Du Brey as Landlady

Harry Tyler as Joe Eliot

Ralph Remley as D'Arcy - Singer

Zeffie Tilbury as Mrs. Sanders

Jack Kelly as Banker's Son (uncredited)

Esther Brodelet as Telephone Operator

Tyler Brooke as Mr. Calhoun

Nora Cecil as Miss Jenkins

Davison Clark as Court Attendant at Door

Dick Elliott as Man Laughing at Demo

Edmund Elton as Banker at Demo

Fern Emmett as Mac Gregor's Maid

Mary Field as Piano Player

George Guhl as Mr. Winthrop

Otto Hoffman as Pawnbroker

Warren Jackson as Tom

Frank Jaquet as Edward

Sheldon Jett as New England Telephone Company Executive

Edward Keane as Banker at Demo

Crauford Kent as General

Edward LeSaint as Banker at Demonstration

Jarold Clifford Lyons as Infant

Dave Morris as Telegrapher

Ottola Nesmith as Nora

Ruth Robinson as Nurse

John Graham Spacey as Sir John Cowell

Landers Stevens as Manager of New England Telephone Exchange

Charles Tannen as Court Clerk

William Wagner as

Eddy Waller as Storekeeper

Jack Walsh as James J. Starrow

Lillian West as Sanders' Nurse

John Elliott as Banker at Demo