Ryō Tagaya

is a Japanese politician who served as a member of the House of Representatives, in Japan's National Diet, from 2021 to 2026. He represented the Southern Kanto proportional representation block.

Tagaya was previously a member of Reiwa Shinsengumi, a left-wing populist opposition party led by Tarō Yamamoto. The party is known for progressive stances, including strong criticism of Israel's actions in Gaza and pro-Palestinian positions. In early January 2026, Tagaya participated in a parliamentary delegation visit to Israel, where he met with Prime Minister Benjamin Netanyahu. This action drew significant backlash from within Reiwa Shinsengumi and its supporters, who viewed it as inconsistent with the party's anti-war line, especially amid the Israel-Gaza conflict. As a result, he left the party.

Following his departure, Tagaya joined the Centrist Reform Alliance. The alliance endorsed him as a candidate for Chiba's 11th district in the 2026 Japanese general election.