Hiroki Otsu (大津弘樹, Ōtsu Hiroki, born 25 May 1994) is a Japanese racing driver who is currently competing in Super GT with ARTA, and in Super Formula for TCS Nakajima Racing as a substitute driver for Naoki Yamamoto.

He took five podiums and finished third in the final standings with 108 points, behind Sho Tsuboi and Tadasuke Makino.

With 79 points, he finished fifth in the final standings behind Mitsunori Takaboshi, Sho Tsuboi, Álex Palou and Ritomo Miyata.

In 2020, Otsu made the move to the GT500 class in Super GT, sharing a Honda NSX-GT GT500 with Takuya Izawa for the Modulo Nakajima Racing team.

[6] At the end of the year, he made his debut in the Super Formula season finale with the TCS Nakajima Racing team at Fuji, replacing Tadasuke Makino who suffered from meningitis and needed rest.

[8] He went on to get his first pole position in the series and win the race in the sixth round of the season at Motegi.

He replaces Tomoki Nojiri, Toshiki Oyu, and Naoki Yamamoto at Mugen, TGM Grand Prix, and Nakajima Racing respectively.