| Floris III | |
| Succession: | Count of Holland |
| Reign: | 1157–1190 |
| Predecessor: | Dirk VI |
| Successor: | Dirk VII |
| Spouse: | Ada |
| Issue: | Dirk VII |
| Royal House: | Holland |
| Father: | Dirk VI |
| Mother: | Sophia of Rheineck |
| Birth Date: | c. 1141 |
Floris III (1141 – August 1, 1190) was the count of Holland from 1157 to 1190. He was a son of Dirk VI and Sophia of Rheineck, heiress of Bentheim.
Floris III was a loyal vassal to Emperor Frederick Barbarossa. He accompanied the emperor on two expeditions to Italy in 1158 and 1176–1178. Frederick thanked him by making Floris part of the imperial nobility. The emperor gave Floris the toll right of Geervliet, the most important toll station in Holland at that time. This was actually the legalisation of an existing situation, because the counts of Holland had charged tolls illegally since the start of the 11th century.
Many farmers came to Holland to turn the swamps into agricultural lands. Dikes and dams were built and the border between Holland and the bishopric of Utrecht had to be determined. There was a dispute between Floris and the bishop of Utrecht about a new dam in the Rhine at Zwammerdam in 1165, which had to be settled by emperor Frederick. The brother of Floris, Baldwin, became bishop of Utrecht in 1178.
War broke out between Flanders and Holland. Count Philip I of Flanders wanted to have Zeeland back. Floris was captured in Bruges and had to accept Flemish overlordship in Zeeland as ransom in 1167. During his reign Floris III had troubles with West Friesland and a war with Philip concerning their respective rights in West Zeeland, in which he was beaten. In 1170 a great flood caused immense devastation in the north and helped to form the Zuider Zee.
In 1189 Floris accompanied Frederick Barbarossa upon the Third Crusade, of which he was a distinguished leader. He died in 1190 at Antioch of pestilence and was buried there. He was succeeded by his son Dirk VII.
In 1162, Floris married Ada, sister of King William the Lion of Scotland. The county of Holland adopted from him the rampant lion in the coat of arms and the name of William. Their children were: