Ormsavatnet is a lake in the municipality of Bykle in Agder county, Norway. The 3.11-square-kilometre (1.20 sq mi) lake flows into the Vatndalsvatnet via a dam and canal. The lake is located in the Setesdalsheiene mountains near the lakes Store Urevatn, Holmevatnet, and Hartevatnet. The nearest village area is Hovden, about 14 kilometres (8.7 mi) to the northeast. The mountain Kaldafjellet lies about 5 kilometres (3.1 mi) to the west of the lake.

• List of lakes in Aust-Agder
• List of lakes in Norway