Leonard was born in 1923 in Whitechapel, London to Abraham Wolfsdorf and Pearl née Pearlman and had a younger brother Charles. In 1939, the family lived at 28 Hawkins Street, Stepney where Leonard’s father Abraham (Alfred) worked as a taxi driver. Leonard was a member of the Victoria Boys and Girls club and was a talented table tennis player. After his death a cup at the club was established as the Leonard Waldorf Cup for Table Tennis in his memory. After school Leonard trained as a pilot and worked for Imperial Airways in 1939 before volunteering underage in the RAF.

A 1942 article in the Jewish Chronicle writes about letters that were received from Leonard whilst he was training at the Polaris Flight Academy in California and his meeting with Mickey Rooney and Deanna Durbin in Hollywood.

On the night of 12/13 May 1943 thirteen Wellington aircraft departed from RAF Ingham for operations at Duisberg. Leonard was the pilot of Wellington HE702 which failed to return and crashed near Nunspeet in Netherlands. The crew are buried in Harderwijk General Cemetery, Netherlands and there is a mounted propeller memorial to the crew at Guelders, Doornspijk.

Pilot, Leonard Waldorf
Nav, Ronald Hughes, 1450608
A/B, John Guyer Wilson, 1386132
W/Op, A/G, Ronald Hermon Downes Cook, 127864
A/G, Tom Warmby, 1236751