Events from the year 1990 in Croatia.

• President – Franjo Tuđman
• Prime Minister – Josip Manolić

• January 1 — A new convertible Yugoslav dinar is introduced to combat inflation, at an exchange rate of 10,000 old dinars for 1 new convertible dinar.
• February 14 — The Parliament of the Socialist Republic of Croatia (SR Croatia) adopts constitutional amendments 54 to 63, paving the way for free and democratic elections.
• April 22–May 7 — First democratic election.
• May 5 — 1990 Eurovision Song Contest hosted in Zagreb's Vatroslav Lisinski Concert Hall.
• May 13 — Dinamo Zagreb-Red Star Belgrade riot occurred at Stadion Maksimir in Zagreb.
• July 26 — Croatian national news service HINA founded.
• August 1 — SAO Krajina proclaimed autonomy.
• August 17 — Log Revolution.
• September 7 — Lučko Anti-Terrorist Unit founded.
• October 10 — National postal service Hrvatska pošta (Croatian Post) established.
• December 21 — The flag of Croatia, designed by Miroslav Šutej, adopted.
• December 22 — The new Constitution of Croatia adopted.

• Brethren of the Croatian Dragon reestablished after being banned by the Communist government in 1946.

• Croatia played the United States on October 28 in the country's first international football match.
• Jugoplastika Split became Euroleague champion.
• Croatia Open Umag tennis tournament was held for the first time.
• European Championships in Athletics was held in Split.

• June 21 — Sandra Perković, discus thrower
• June 30 — Sandro Sukno, water polo player
• August 17 — Ivan Šarić, chess player
• November 14 — Tereza Mrdeža, Croatian tennis player

• February 4 — Toma Bebić, singer-songwriter (b. 1935))
• February 24 — Jure Kaštelan, poet (b. 1919)
• June 7 — Petar Šegvić, rower (b. 1930)
• July 31 — Lovro Radonić, water polo player and butterfly swimmer (b. 1928)
• August 10 — Joško Vidošević, footballer (b. 1935)
• September 12 — Ivo Kurtini, water polo player (b. 1922)
• September 24 — Zlata Kolarić-Kišur, writer (b. 1894)
• September 25 — Vjekoslav Vrančić, Ustase official (b. 1904)
• October 4 — Matija Skurjeni, painter (b. 1898)
• November 30 — Ivan Medarić, footballer (b. 1912)