The Bay-ringed Tyrannulet (Phylloscartes sylviolus) is a species of bird in the Tyrannidae family. It is found in Argentina, Brazil, and Paraguay.

Its natural habitat is subtropical or tropical moist lowland forests. It is becoming rare due to habitat loss.

Source

• BirdLife International 2004. Phylloscartes sylviolus. 2006 IUCN Red List of Threatened Species. Downloaded on 26 July 2007.