Tony Hans-Joachim Martin (born 23 April 1985) is a German former professional road bicycle racer. Martin was known as a time trial specialist, and is a four-time world champion in the discipline – having won the title in 2011, 2012, 2013 and 2016 – which is joint-most with Fabian Cancellara. He also won a silver medal at the 2012 Summer Olympics in London, finishing runner-up to Bradley Wiggins in the event. Martin was also part of four world championship-winning team time trial squads, with Omega Pharma–Quick-Step/Etixx–Quick-Step, in 2012, 2013 and 2016, and with Germany in the mixed relay time-trial in 2021.

Martin won seven Grand Tour stages, including five individual time trial stages – three at the Tour de France in 2011, 2013 and 2014, and two at the Vuelta a España in 2011 and in 2014. In the mid-part of his career Martin was a successful stage racer, winning the Eneco Tour (2010), Paris–Nice (2011) and the first two editions of the Tour of Beijing in 2011 and 2012. In the latter part of his career he became a super-domestique and road captain at Team Jumbo–Visma.