“Cashel Byron's Profession” is a novel by George Bernard Shaw, an Irish playwright who became the leading dramatist of his generation, and in 1925 was awarded the Nobel Prize in Literature.

Cashel Byron's Profession is George Bernard Shaw's fourth novel. Shaw wrote five novels early in his career and then abandoned them to pursue politics, drama criticism, and eventually playwriting. 

The novel follows Cashel Byron, a world champion prizefighter, as he tries to woo wealthy aristocrat Lydia Carew without revealing his illegal profession.