The basic units of regional self-government are the counties (županija in Croatian). The present administrative territorial division of the country was introduced in 1997, when the 1992 division was changed. Smaller administrative territorial units within counties are cities/towns in urban areas, and municipalities in other areas. According to the 2006 Act, Croatia has 127 towns/cities and 428 municipalities.

The county, as a unit of territorial division in Croatia, has a long history. Counties are mentioned as early as the 10th century, first in the southern part of the country, and later in the north. They continued to exist up to the 20th century, in different numbers and with changing territorial ranges, means of organisation and powers. After the demilitarisation of the Military Border in 1881, there were 8 counties in the Kingdom of Croatia and Slavonia: Modruš-Rijeka, Lika-Krbava, Zagreb, Varaždin, Bjelovar-Križevci, Požega, Virovitica and Srijem.

The Counties and the City of Zagreb

I. Zagreb County
Administrative centre: Zagreb
Number of inhabitants (2021): 299,985
Surface area in km²: 3,060
II. Krapina-Zagorje County
Administrative centre: Krapina
Number of inhabitants (2021): 120,702
Surface area in km²: 1,229
III. Sisak-Moslavina County
Administrative centre: Sisak
Number of inhabitants (2021): 139,603
Surface area in km²: 4,468
IV. Karlovac County
Administrative centre: Karlovac
Number of inhabitants (2021): 112,195
Surface area in km²: 3,626
V. Varaždin County
Administrative centre: Varaždin
Number of inhabitants (2021): 159,487
Surface area in km²: 1,262
VI. Koprivnica-Križevci County
Administrative centre: Koprivnica
Number of inhabitants (2021): 101,221
Surface area in km²: 1,748
VII. Bjelovar-Bilogora County
Administrative centre: Bjelovar
Number of inhabitants (2021): 101,879
Surface area in km²: 2,640
VIII. Primorje-Gorski Kotar County
Administrative centre: Rijeka
Number of inhabitants (2021): 265,419
Surface area in km²: 3,588
IX. Lika-Senj County
Administrative centre: Gospić
Number of inhabitants (2021): 42,748
Surface area in km²: 5,353
X. Virovitica-Podravina County
Administrative centre: Virovitica
Number of inhabitants (2021): 70,368
Surface area in km²: 2,024
XI. Požega-Slavonia County
Administrative centre: Požega
Number of inhabitants (2021): 64,084
Surface area in km²: 1,823
XII. Brod-Posavina County
Administrative centre: Slavonski Brod
Number of inhabitants (2021): 130,267
Surface area in km²: 2,030
XIII. Zadar County
Administrative centre: Zadar
Number of inhabitants (2021): 159,766
Surface area in km²: 3,646
XIV. Osijek-Baranja County
Administrative centre: Osijek
Number of inhabitants (2021): 258,026
Surface area in km²: 4,155
XV. Šibenik-Knin County
Administrative centre: Šibenik
Number of inhabitants (2021): 96,381
Surface area in km²: 2,984
XVI. Vukovar-Srijem County
Administrative centre: Vukovar
Number of inhabitants (2021): 143,113
Surface area in km²: 2,454
XVII. Split-Dalmatia County
Administrative centre: Split
Number of inhabitants (2021): 423,407
Surface area in km²: 4,540
XVIII. Istra County
Administrative centre: Pazin
Number of inhabitants (2021): 195,237
Surface area in km²: 2,813
XIX. Dubrovnik-Neretva County
Administrative centre: Dubrovnik
Number of inhabitants (2021): 115,564
Surface area in km²: 1,781
XX. Međimurje County
Administrative centre: Čakovec
Number of inhabitants (2021): 105,250
Surface area in km²: 729
XXI. The City of Zagreb
Number of inhabitants (2021): 767,131
Surface area in km²: 641