Hirooki Arai

is a male Japanese racewalker. He competed in the 50 kilometres walk event at the 2015 World Championships in Athletics in Beijing, China.

He finished third in the 50-kilometre race walk event at the 2016 Rio Olympics, but was subsequently disqualified following his collision in the final kilometres with Evan Dunfee of Canada, who then moved up from fourth place to claim the bronze medal. He had it given back to him after a few minutes when a Japanese appeal overturned the disqualification.