Leonard Oliver Connelly was born on September 15th, 1926 in Winnipeg, Manitoba. His mother was Louise Mary Connelly, and his father was James Frederick Connelly. His father served in WWI with the 21st Battalion CEF. He had two older brothers, and six younger siblings; four sisters and two brothers. He lived in Sudbury, Ontario, never married, and worked in a saw mill for two years before the war. His interests were hockey, baseball and photography.

He enlisted on August 26th, 1942 in Sudbury with the intention of joining the Lake Superior Regiment. Being 16 years old at the time, he lied about his age on his application and said he was born 25 Aug 24. He was originally attached to #2 District Depot, and was transferred to A-30 CITC in Utopia, New Brunswick to complete his basic training from 17 Nov 42 to 22 Feb 43. Following this, he was sent to CSTC Kingston on 23 Feb 43, where he later was charged 15 days pay for being A.W.L from 16 Mar 43 to 30 Mar 43. He was qualified as an Infantry Signaller on 25 Jun 43, and was granted furlough until being posted overseas on 21 Jul 43. He was attached to the 1st Canadian Signal Reinforcement Unit on 28 Jul 43 upon arrival in the United Kingdom. He was deducted a total of five days pay for being A.W.L for two days on 28 Sept 43. On the last day of his forfeited pay, he was A.W.L for an hour and a half, and was charged an additional 21 days pay as a result. He transferred to 5th Canadian Infantry Reinforcement Unit on 28 Oct 43, and again was charged A.W.L for two hours on 12 Nov 43, and forfeited seven days pay. He was transferred again to 4th Canadian Infantry Reinforcement Unit on 20 Nov 43, and again, was charged fourteen days pay for being A.W.L on 04 Dec 43 for a day. He was again A.W.L from 23 Dec 43 to 02 Jan 44, and was charged 39 days pay as a result. Furthermore, he was placed in detention for 144 hours and charged six days pay for an unknown offence, then was A.W.L for five hours on 28 Jan 44 and charged 28 days pay. He was A.W.L again on 01 Feb, and again on 03 Feb. He was given a 15 day suspension on 16 Feb 44, and sent to Italy on 17 Feb 44, arriving a day later.

He joined the 48th Highlanders on 03 Mar 44 while in Italy. He was wounded in battle on 17 Sept 44. That same day, his appointment of Acting Lance Corporal from the week before was removed. He left Italy on 11 Mar 45 and arrived in France two days later. He was killed in action on 13 Apr 45, while serving with Able Coy during Operation Cannonshot in Twello, Holland.