Petr Mrázek (Czech: [ˈmraːzɛk]; born 14 February 1992) is a Czech professional ice hockey goaltender currently signed with the Toronto Maple Leafs of the National Hockey League (NHL).
He was selected in the fifth round, 141st overall, by the Detroit Red Wings in the 2010 NHL Entry Draft, with whom he spent the first portion of his NHL career. He also played for the Philadelphia Flyers and Carolina Hurricanes.
Before going to North America, Mrázek played in the Czech Extraliga, where he appeared for HC Vítkovice Steel during the 2007–08 post-season.
In his first Ontario Hockey League (OHL) season with the Ottawa 67's in 2009–10, Mrázek posted a 12–9–1 record in 30 games with a 3.00 goals against average (GAA) and .905 save percentage. He played in eight playoff games with Ottawa, finishing with a 4–4–0 record, 2.39 GAA and a .928 save percentage. At the end of the season, at the 2010 NHL Entry Draft from 25 and 26 June, Mrázek was selected by the Detroit Red Wings in the fifth round, 141st overall.
On 19 October 2011, Mrázek signed a three-year, entry-level contract with the Red Wings. However, he remained in the OHL for the 2011–12 season, appearing in 50 regular season games for the 67's. He was 30–19 with three shutouts and had a 2.84 GAA and .917 save percentage in the regular season. In the playoffs, he appeared in 17 of 18 games, going 9–8 with a 2.59 GAA and .929 save percentage.
On 4 April 2011, upon the conclusion of Ottawa's season, Mrázek was signed by the Grand Rapids Griffins, the Detroit Red Wings' American Hockey League (AHL) affiliate, on an amateur try-out contract.