He was born in Dundas, Ontario and became a merchant and textile dyer by career.

After serving his first term in Parliament, he was defeated there in the 1940 election by Ellis Hopkins Corman.

Lennard returned to the House of Commons when he won the seat back in the 1945 election and won consecutive elections until he left federal politics in 1962 after completing his final term, the 24th Parliament.

[3] Lennard was also a one time Canadian delegate to the United Nations.

In 1957, then Prime Minister John Diefenbaker had appointed Lennard for the position of Canadian delegate in New York at the U.N general Assembly.