Rohan Craig Dennis (born 28 May 1990) is an Australian former cyclist, who competed professionally in the track and road disciplines of the sport for five different teams.

Having been a member of the Australian team pursuit squad that won consecutive world titles at the UCI Track Cycling World Championships in 2010 and 2011, Dennis transitioned to road racing in 2013. Dennis took more than thirty wins in his career, the majority coming in individual time trials – including consecutive wins at the UCI Road World Championships in 2018 and 2019, four Australian National Time Trial Championships victories, and stage wins at all three Grand Tours. He also won the 2015 Tour Down Under and is a former holder of the Union Cycliste Internationale's hour record, having completed a distance of 52.491 kilometres (32.616 miles) in 2015.

On 31 December 2023, Rohan Dennis was involved in a fatal incident in which a vehicle he was driving struck and killed his wife, Olympian Melissa Hoskins, outside their home in Adelaide. In December 2024, Dennis pleaded guilty to an aggravated charge of creating a likelihood of harm.