Sedlak or Sedlák is a Czech surname, which means a "peasant farmer" or "freeman farmer" who was relatively wealthy and owned his own land. The name may refer to:

• Anthony Sedlak (1983–2012), Canadian chef
• Borek Sedlák (born 1981), Czech ski jumper
• Gabriela Sedláková (born 1968), Czech athlete
• Jan Sedlák (born 1994), Czech footballer
• Katerina Sedláková (born 1990), Czech basketball player
• Miroslav Sedlák (born 1993), Slovak footballer
• Oldrich Sedlák (1922–1985), Czech ice hockey player
• Pavol Sedlák (born 1979), Slovak footballer
• Tomáš Sedlák (born 1983), Slovak footballer
• Wlodzimierz Sedlak (1911–1993), Polish biochemist