Hiroshi Suzuki took up swimming at a young age and began being recognized for his talents as a high school student. His performances led him to be selected to represent Japan at the 1952 Helsinki Olympics, where he took silver in the 100 metres freestyle and the 4x200 metres freestyle relay, alongside Yoshihiro Hamaguchi, Toru Goto, and Teijiro Tanikawa. He then won gold in those events at the 1954 Asian Games, in the latter with Tanikawa, Yukiyoshi Aoki, and the non-Olympian Kenzo Yoshimura. He attempted to repeat these feats at the 1956 Melbourne Olympics, but was ninth in the 100 metres and fourth with the relay, alongside Manabu Koga, Atsushi Tani, Koji Nonoshita, and Tsuyoshi Yamanaka. In-between, however, he set a world record in the 4x100 metres freestyle relay in 1955 that lasted for nearly three years. After retiring from active competition, he worked in business management.