Mrázek (feminine Mrázková) is a Czech surname. Notable people include:
- František Mrázek, controversial Czech entrepreneur
- František Mrázek (ice hockey), Czech ice hockey player
- Giedrė Lukšaitė-Mrázková, Lithuanian harpsichordist
- Ivan Mrázek, Czech basketball player and coach
- Jana Mrázková, Czech figure skater
- Jaroslav Mrázek, Czech ice hockey player
- Jerome Mrazek, Canadian ice hockey goaltender
- Petr Mrázek, Czech ice hockey player
- Robert J. Mrazek, politician and author from New York
- Roman Mrázek, race walker who represented Czechoslovakia and later Slovakia
- Tomáš Mrázek, professional Czech rock climber
- Václav Mrázek, Czech serial killer