Geoffrey Lehmann was born in Sydney on 28 June 1940 and spent his early childhood at McMahon's Point. He attended the Sydney Church of England Boys' Grammar School before continuing on to the University of Sydney, where in addition to studying Arts and Law, he co-edited magazines with Les Murray, with whom he co-published his first book of poetry The Ilex Tree.

Part of the Sydney Push, Lehmann has often satirised Sydney life. In addition to his many poetry collections, including Poems 1957-2013, (UWAP 2014) which won the Prime Minister's prize for poetry. He has edited many poetry anthologies, including Australian Poetry Since 1788, edited by Geoffrey Lehmann, Robert Gray, published 2011 by UNSW Press.

His other books are textbooks on tax, for he was a partner at PriceWaterhouseCoopers and has lectured in tax law at UNSW.