Jack was born to Richard and Mary Leech in Shrewsbury, England, about 1872. He served in the Boer War and had worked as a School Master prior to coming to Australia about 1904. At Inverell he was employed as an Orchardist for Mr. Lewin at his property, Clinton. Jack enlisted at Inverell on 10 January 1916 following the large recruiting rally held just prior to the departure of the First Contingent of The Kurrajongs.
He trained at Armidale and Rutherford with the 33rd Battalion, 4th Reinforcement which sailed from Australia on HMAT A30 Borda in October 1916. After arriving in England in January 1917 he attended the School of Musketry at Tidsworth for a month, qualifying 1st Class. Later that year he was attached to the 9th Training Battalion until sent to France at the end of January 1918. Two months later he became ill with Trench fever and the decision was made to return him to England partly due to his age. He was then appointed Sergeant with No 2 Com Depot. At the beginning of February 1919 he was granted three months leave to work in Dairy Farming at Haston Farm, Hadnall, Shrewsbury.
Jack returned to Australia in November 1919 and was discharged in February 1920. He was a prominent member of the Inverell Agricultural Bureau both before and after the War. In later years he worked at the Oxford Hotel. Jack died at Inverell in 1940 and was buried in the Church of England section of the Cemetery.
Sergeant Jack Leech is remembered at Inverell where his name is inscribed on the town’s Honor Roll.