Mierzyn [ˈmjɛʐɨn] is a village in the administrative district of Gmina Sędziszów, within Jędrzejów County, Świętokrzyskie Voivodeship, in south-central Poland. It lies approximately 6 kilometres (4 mi) east of Sędziszów, 12 km (7 mi) south-west of Jędrzejów, and 47 km (29 mi) south-west of the regional capital Kielce.