Lynnton Ainsley Martin was born on 21 September 1913 at Kaniva, Victoria, to James Lewis Martin and Mary Jane Martin (nee Taylor). He had one brother, Malcolm Murray Martin. The family lived in several towns in North-West Victoria for over a decade before moving to Mornington, Victoria.

Martin became a grocery salesman. He married Norah Marchant in 1937. They continued to live at Mornington, and had two sons.

On 23 May 1941, Martin enlisted to the Royal Australian Air Force at Melbourne, Victoria. He undertook basic pilot training at several stations in Victoria, and received his Flying Badge on 12 December 1941. After completing further training, he was assigned to the No. 2 Squadron on 4 March 1943. Martin joined the squadron in Darwin, Northern Territory, operating Hudson bombers in reconnaissance and bombing missions against the Japanese throughout the Dutch East Indies.

On 8 September 1943, Martin was on an operation near the Tanimbar Islands. His aircraft was shot down by Japanese anti-aircraft fire, and Martin, alongside two other members of his crew, was killed in the crash. The remaining two members of his crew were captured as prisoners of war and executed shortly thereafter.

Lynnton Ainsley Martin is commemorated at Northern Territory Memorial at the Adelaide River War Cemetery, Northern Territory.