Floris IV was the count of Holland from 1222 to 1234. He was born in The Hague, a son of William I of Holland and his first wife, Adelaide of Guelders.
Floris succeeded his father in 1222. His regent was Baldwin of Bentheim. He acquired the Land of Altena. He had constant disputes with the bishop of Utrecht, Otto II of Lippe, but helped him against the peasants of Drenthe in 1227. Floris fought in the crusade against the Stedinger north of Bremen in 1234.
On 19 July 1234, he was killed at a tournament in Corbie, France. He was buried at Rijnsburg Abbey.