Boris Vyacheslavovich Gryzlov (also spelled Grizlov; Russian: Борис Вячеславович Грызлов, Russian pronunciation: ) (born December 15, 1950), is a Russian politician and current Speaker of Russia's State Duma (the lower house of parliament). He is one of the leaders of the largest Russian political party, United Russia. Boris Gryzlov is a close ally of Russian Prime Minister Vladimir Putin.

Gryzlov was born in Vladivostok but was raised in Leningrad (Saint Petersburg). He graduated from the Leningrad Electrical Institute of Communications in 1973 and worked as a radio engineer. From 1977 to 1996 he worked his way up from being an engineer to division director in the Elekronpribor plant. He was not a public figure before 1999. In October 1999 he became head of the St Petersburg regional branch of Sergey Shoygu's Unity party and in December 1999 he was elected to the Russian Duma running on the Unity party ticket. In January 2000 he was elected chairman of the Unity faction in the Duma.

In March 2001 he was appointed to the post of chief of Russian police and became Russia's Interior Minister. In this position Gryzlov proclaimed that the fight against terrorism and corruption were his priorities. He is responsible for the notorious "werewolves in epaulets" (rus. oborotni v pogonah) investigation into corrupt police officers. The expression "werewolves in epaulets", coined by Gryzlov to indicate corrupt officers, was picked up by the Russian media and Runet, and soon became a popular saying and the inspiration for many jokes. Critics accused Gryzlov of using this investigation to gain more popularity before 2003 parliamentary elections.