Haddon was born Peter Haddon Tildsley in
Rawtenstall,
Lancashire. He was the son of Alfred and Mary Tildsley; he had a brother, Vincent Harvey (born 1894), and two sisters, Edna and Mary. His father was a clergyman. In 1925, he married Rosaline Jane Courtneidge (1903–1926), a daughter of
Robert Courtneidge; her eldest sister was
Cicely Courtneidge. Peter and Rosaline Tildsley had a daughter, Rosaline (1926–2011). In 1932, as a widower, he married divorcee Edith Ralston Hicks Lyon, née Huxtable. By 1945 she had remarried. ==Career==