[1] Donald Platt was born in Toronto, Ontario, Canada on 5 June 1930.

[4][1] He won his one and only singles title in 1953 at the Toronto District Championships against Beau Summers.

[1] In addition he was a finalist at the Leaside Invitation in 1954 against Jim Bentley, and the Toronto District Championships again in 1955.

[5] In 1960 he reached his last tournament final at the Ontario International Championships losing to Donald Fontana.

[1] Following his retirement he was working as a tennis writer for the Toronto Star in the early 1970s.