Masakazu Sekiguchi

is a Japanese politician of the Liberal Democratic Party who has served as the President of the House of Councillors since 2024.

Born in Saitama Prefecture, Sekiguchi was a dentist and a member of the Saitama Prefectural Assembly before his first election to the House of Councillors in 2003. He served as parliamentary vice minister for Foreign Affairs, senior vice minister for Internal Affairs and Communications and chairman of the LDP caucus in the House of Councillors, before he was elected President of the House of Councillors in 2024.

Biography Masakazu Sekiguchi was born on 4 June 1953 in Minano, Saitama, to a family of dentists. His father Keizo Sekiguchi was president of the Saitama Dental Association and a member of the House of Councillors for the LDP from 1980 to 1992. Sekiguchi was educated at the Josai Dental University, currently Meikai University. After graduating in 1979, he worked at his family's dental clinic.

Sekiguchi was elected to the Saitama Prefectural Assembly in 1995, as a member of the LDP. In 2003 he ran for the House of Councillors in Saitama at-large district by-election, as the incumbent Takujiro Hamada had resigned to run for governor. Sekiguchi defeated Chiyako Shimada of the Democratic Party and was elected for the first time. He has subsequently been returned four times.

In 2006, Sekiguchi received his first government position as parliamentary vice minister for foreign affairs under the First Abe Cabinet. He became chairman of the committee on Education, Culture, Sports, Science and Technology in the House of Councillors the following year, serving until 2008. He then served as senior vice minister for Internal Affairs and Communications under the Second Abe Cabinet from September 2013 to September 2014. In 2019, he was elected Chairman of the LDP in the House of Councillors. He was elected President of the House of Councillors in November 2024, when Hidehisa Otsuji resigned for health reasons.