Major-General Lessard was born in Iserlohn, Germany. He joined the Canadian Forces under the Regular Officer Training Plan and graduated from the Collège Militaire Royal in Saint-Jean with a degree in Business Administration in 1978.

Upon commissioning, he served in a variety of regimental positions with the 1st and 3rd Battalions of the Royal 22e Regiment in Lahr and Valcartier. He also served with the Canadian Airborne Regiment in Petawawa.

From 1992 to 1994, Major-General Lessard commanded the 3rd Battalion and the 1st Battalion of his Regiment. He later commanded the Combat Training Centre as well as Canadian Forces Base Gagetown from 1997-99. As such, he was responsible for the Army's Individual Training. On posting to Kingston, he was appointed as Commandant of the Canadian Land Force Staff College from 1999-2001 and was subsequently appointed as the Deputy Commander, Striking Fleet Atlantic, in Norfolk, USA. During this posting, he was responsible for the preparation and the certification of Striking Fleet Atlantic as NATO's first operational Combined Joint Task Force Headquarters.

His staff experience includes two postings with the 1st Canadian Division Headquarters in Kingston. He was a member of the Canadian Forces Officer Development Review Board that oversaw training and education for the Canadian Officer Corps. He attended the Canadian Land Force Staff College as well as the British Army Staff College.

Amongst his operational experience, Major-General Lessard served overseas in Cyprus in 1985 as company second in command. He commanded the 1R22eR Battalion Group in Croatia with UNPROFOR in 1993-94. During this time his unit received the Commander UNPROFOR's Unit Commendation for excellence in operations in the Medak, Benkovac, and Obrovac Areas. He returned a second time to ex-Yugoslavia as Deputy Commander 5 Canadian Multinational Brigade in Bosnia with IFOR in 1996.

Major-General Lessard assumed Command of LFCA on 3 July 2003, an appointment he held until 3 February 2005, at which time he was promoted to his present rank and appointed Assistant Chief of the Land Staff.