Richard Horatio Edgar Wallace was a British writer of sensational novels, plays and detective, gangster, adventure and science fiction stories.

Wallace's great-grandfather was entertainer James Henry Marriott, and his grandmother was actress Alice Marriott. Wallace was born at 7 Ashburnham Grove, Greenwich, to actors Richard Horatio Marriott Edgar (1847–1894) and Mary Jane "Polly" Richards, née Blair (born 1843).

Wallace's mother's family had been in show business, and she worked in the theatre as a stagehand, usherette, and bit-part actress until she married in 1867. Her husband, Captain Joseph Richards, was born in 1838; he was from an Irish family. He and his father John Richards were both Merchant Navy captains, and his mother Catherine Richards came from a mariner family. Joseph died at sea in 1868, leaving his pregnant wife destitute. After the birth of Wallace's older sibling, his mother returned to the stage, assuming the stage name "Polly" Richards. In 1872, she met and joined the Marriott family theatre troupe, managed by Alice Marriott, her husband Richard Edgar, and her three adult children (from earlier liaisons), Grace, Adeline and Richard Horatio Marriott Edgar.

In December 1931, Wallace was assigned work on the RKO "gorilla picture" (King Kong, 1933) for producer Merian C. Cooper. By late January, however, he was beginning to suffer sudden, severe headaches and was diagnosed with diabetes. His condition deteriorated within days. Violet booked passage to California on a liner out of Southampton, but received word that Edgar had slipped into a coma and died of the condition, combined with double pneumonia, on 10 February 1932 in North Maple Drive, Beverly Hills. The flags on Fleet Street's newspaper offices flew at half-mast, and the bell of St. Bride's tolled in mourning. His body was returned to England and he was buried at Little Marlow Cemetery, Fern Lane, Buckinghamshire, not far from his UK country home, Chalklands, in Bourne End.