Dmitry Nikolayevich Kozak (born November 7, 1958) is a Ukrainian-born Russian politician, serving since October 2008 as deputy Prime Minister of the Russian Federation. He is known as the Cheshire Cat because of his smile and is part of the Vlast' or power group from St. Petersburg close to Putin.

Dmitry Kozak is known as a close ally of Vladimir Putin, having worked with him in the St Petersburg city administration during the 1990s and later becoming one of the key figures in Putin's presidential team. During the 2004 Russian presidential election he was head of Putin’s election campaign team. Kozak was one of several members of Putin's circle touted in the media as a possible candidate to succeed Putin as president in 2008.

In 2014, Kozak was added to the US and EU sanctions lists due to his role in the 2014 Crimean crisis.