Art and music have been two of the guiding principals in Leitch's life. He worked for a time as a professional musician before committing fully to a career as a painter. The son of Christchurch based artist, Peter Leitch, Lawrence attended Wellington Polytechnic School of Design and on completion of his studies worked as a commercial artist. In the late 1980s Leitch spent time in the United States studying and working. On returning to New Zealand he became further involved in seriograph printmaking which lead to commercial success. In 1995 he was awarded a Gold Medal at the 1995 New Zealand Pride in Print Awards.
Leitch initally produced fine watercolours of outstanding quality featuring the landscapes of Central Otago, Coromandel and Auckland. In 2001 the artist began working on dramatic large scale acrylics. These dynamic works have enjoyed worldwide patronage and appreciation. There is a consistency in Leitch's work in that the human element is suggested but not focused on. Derelict rural buildings, windblown tussock foregrounds framed by azure skies echo a haunting stillness. It is a tribute to the artist's versatility that he is able to capture the extreme contrasts of both the North and South Islands.