Thomas Pennington Lucas (13 April 1843 – 15 November 1917), also known as T.P. Lucas, was a Scottish-born Australian medical practitioner, naturalist, author, philosopher and utopianist.
Lucas was born in Dunbar, Scotland to Samuel Lucas, a Wesleyan Methodist minister, and Elizabeth Broadhurst. Lucas inherited from his father a love of natural history and a lifelong determination to reconcile his strong religious beliefs with his scientific convictions, as evidenced in many of his books. Because his father was often on the move to new postings, taking his family with him, Thomas was educated at King Edward VI Grammar School at Stratford-on-Avon, Helston Grammar School, Cornwall, and New Kingswood School in Bath.
Having developed tuberculosis, in 1876 Thomas Lucas migrated to Melbourne, Australia where he set up a medical practice. His three living children joined him there in 1879 after being cared for by his brother, Arthur Henry Shakespeare Lucas. Arthur followed him to Melbourne in 1883 and became a well known biologist and schoolmaster in his own right.
Lucas and his family moved to Brisbane, Queensland in 1886. His medical practice was first set up in central Brisbane, moving in the early 1890s to South Brisbane. Later he relocated to Acacia Ridge south of Brisbane, then finally to New Farm in inner north Brisbane from 1911 until Lucas's death.
A firm believer in the medicinal properties of pawpaws, he developed and marketed Lucas' Papaw Ointment, which is still produced by Lucas's descendants from a location at Beaudesert Road, Acacia Ridge. In 2009 as part of the Q150 celebrations, the Lucas' Pawpaw Ointment was announced as one of the Q150 Icons of Queensland for its role as an iconic "innovation and invention".