Lawrence Day (born February 1, 1949 in Kitchener, Ontario) is a Canadian chess International Master, author, and journalist. He has represented Canada at 13 Chess Olympiads.
As a youth in Ottawa, Day came under the influence of Fedor Bohatirchuk, a strong Ukrainian International Master and doctor, who had emigrated to Canada after the Second World War. Day's progress was rapid, and he qualified through the 1966 Open Canadian Chess Championship at Kingston, to represent Canada at the 1967 Junior World Chess Championship at Jerusalem, where he qualified for the 'A' final group. The highly experienced Bohatirchuk, who had a 3-0 score against Mikhail Botvinnik (later World Champion) exerted a very strong influence on Day's playing style.
Day first played for Canada in the Chess Olympiad in 1968 on the first reserve board (+3,=1,-8) at Lugano, his first of 13 appearances, which is a Canadian record. Day played board three for Canada (scoring +7,=1,-2) on the bronze medal team at the World Students' Chess Olympiad, Mayagüez 1971. He graduated from Carleton University in 1972 with a degree in English Literature, worked for the magazine Chess Canada for a time, and then became a professional player. He earned his International Master title at the Zonal Canadian Chess Championship, Toronto 1972.