John H. Millman OLY (born 14 June 1989) is an Australian professional tennis player. He reached a career-high singles ranking of world No. 33 in October 2018. He is coached by German former professional player Jonas Luetjen.
Millman was born in Brisbane, Australia, into a family of five children (four girls) and is the second youngest. During his schooling years he attended Brisbane Grammar School then the Anglican Church Grammar School. Outside tennis he enjoys soccer and supports Liverpool Football Club who compete in the English Premier League. Millman is represented by Sasha Skyba of Skyba Sports Management. In January 2019 Millman received the OLY post-nominal title at the Brisbane International tournament.
Millman made his ITF junior tournament debut in Darwin as a 15-year-old in 2004 and reached the quarterfinals. He made his junior Grand Slam debut at the 2006 Australian Open. He won his first junior tournament in June 2006 at a tournament held in New Caledonia. He then won his next two tournaments in a row held in Fiji and New Zealand respectively. He competed in his last junior tournament at the 2007 Australian Open.