Mrkonjić (Serbian Cyrillic: Мркоњић) is a Serbo-Croatian surname. It may refer to:
People
- Braća Mrkonjić, music duo
- Milutin Mrkonjić (born 1942), Serbian politician
- Novak Mrkonjić
- Petar Mrkonjić (mid-17th century), legendary brigand in Dalmatia
- Peter I of Serbia (1844–1921), nom de guerre Petar Mrkonjić, King of Serbia
- Tomislav Mrkonjić (born 1994), Croatian footballer
- Zvonimir Mrkonjić (born 1938), Croatian writer, poet
Toponyms
- Mrkonjić Grad, a town and municipality in western Bosnia and Herzegovina