Killingly a member of the Eastern Connecticut Conference.  Killingly won the Class M State Championship in 1981, 1996, 2017, and 2021. The 1952 Team finished undefeated and was ranked #8 in the Connecticut AP Poll. The 1953 team also finished undefeated and was ranked 4th in the AP Poll. In 1980, Killingly received a CIAC Merit Award after finishing 9-2. The 1981 team finished 6th overall in Connecticut and 14th in New England, while giving up only 44 points the entire season. The 1994 and 1995 teams also qualified and played in the Connecticut State Playoffs. The 1994 team lost in the State Finals to Brien McMahon. The 1996 State Championship team finished ranked 5th in the New Haven Register Final Poll, and 4th in the Hartford Current Final Poll encompassing all teams in the state. The 2017 Team finished 5th in the GameTimeCT/New Haven Register State Media Poll, and also garnered the 2nd most 1st place votes with 5. The 2017 team finished 6th in The Day coaches poll, and were the only team undefeated in the State of Connecticut at 13 - 0. They were also named the 2017 Team of the Year by the Connecticut High School coaches association. In 2015, the Redmen finished 10 - 2 reaching the Class M' State Semi - Finals after winning a quarter-final game at home against Stratford. Killingly lost at home to eventual champion Brookfield.  Killingly also made the State Playoffs and lost to eventual champion Hillhouse in the Semi -  Finals. The 2018 team also made the State Playoffs and lost in the Semi - Finals to St. Joseph's. The 2019 team made it to the Class M' State Finals, losing to Weston High School. In 2021, Killingly won its 4th State Title and 3rd undefeated season with a 28-14 win over Rockville. The finished ranked #7 in both the GametimeCT Media and The Day Coaches Polss.  In 2022, KHS football finished 11-2, won an ECC Title, and lost to North Haven in the Class MM State Championship game at Rentschler Field.  Killingly has been ECC Champions in 1966, 1980, 1981, 1995, 1996, 2009, 2011, 2015, 2016,  2017, 2018, 2021, and 2022

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Click on link for 2022 CT HS Football Record Book: