The Tri-Valley League or TVL is a high school athletic league located in towns in Middlesex and Norfolk counties, Massachusetts. The league was founded in 1966 by principals and Alfred “Hap’’ Mazukina, who served as the league's commissioner for 23 years. In its infancy the TVL struggled but over the years has undergone changes and is now regarded more than 50 years later as one of the most respected high school sports leagues in Massachusetts.[citation needed]
The league's name is based on the geography of the area, the river valleys of the Charles River, Blackstone River and Taunton River all converge in the region.