Nikola Šubić Zrinski Square (Croatian: Trg Nikole Šubića Zrinskog, popularly referred to as Zrinjevac) is a square and park in Donji Grad, the central part of Zagreb, the capital of Croatia. It is located near the central Ban Jelačić Square, halfway towards the Main Railway Station. It is a part of the so-called Green horseshoe or Lenuci's horseshoe (Croatian: Zelena potkova or Lenucijeva potkova), which consists of seven squares in Donji grad. It is spread over an area of 12,540 square meters (135,000 sq ft).
The southern part of Zrinjevac sports busts of significant Croatian people: Julije Klović, Andrija Medulić, Fran Krsto Frankopan, Nikola Jurišić, Ivan Kukuljević Sakcinski and Ivan Mažuranić.
In the middle of the park is a music pavilion built in 1891.
Several institution are based in buildings around Zrinjevac: