Gaku Hasegawa (長谷川 岳, Hasegawa Gaku, born February 16, 1971) is a member of the House of Councillors of Japan from Hokkaido.

In 1990 he enrolled at Hokkaido University and majored in Business Administration.

The Soran Festival incorporates the traditional Sōran Bushi song and dance.

He has received the Japan Event New Theme Prize, the Suntory Area Culture Prize, and the Japanese Lifestyle and Culture Prize, for his founding of the Yasakoi Soran Bushi Festival that has come to represent the city of Sapporo.

In 2008 he ran against Takahiro Yokomichi of the Democratic Party of Japan for representative of the first district of Hokkaido.