National Day (Croatian: Dan državnosti, pronounced [dan dr̩ʒaʋnosti]) is an annual public holiday and national day celebrated on 30 May in Croatia to celebrate the constitution of the first modern multi-party Croatian Parliament in 1990.

The day is usually marked by family reunions, picnics, barbecues, flag-raising and national anthem-playing ceremonies and by civilian and military parades on quinquennial or decennial anniversaries.

On 25 June 1991, after the independence referendum held on 19 May 1991, Croatia proclaimed its independence, but due to the negotiation of the Brioni Agreement, a three-month moratorium was placed on the implementation of the decision and the Parliament cut all remaining ties with Yugoslavia on 8 October 1991.

On 14 November 2019, the Croatian Parliament adopted a new law on holidays, and moved National Day back to 30 May.

Typical state activities on the occasion involve speeches by the President of Croatia and other dignitaries, as well as commemoration of the Croatian War of Independence.