Alastair I (Alastair Arthur) was the second King of Florida, and the last monarch of the house of Wettin in Florida.
He was born on 9 August, 1914 in the Royal Palace, Tallahassee, Florida, the only child of Crown Prince Arthur of Florida, and his wife Princess Alexandra Duff of Fife. He became King of Florida upon the death of his grandfather, King Arthur I, on 16 January, 1942. Alastair I died the year after, on 26 April, 1943 in the Royal Palace, Tallahassee, succeeded by his cousin Oscar I.
He never married.