[2] Appleton was born and raised in Green Bay, Wisconsin, where he attended Ashwaubenon High School and Notre Dame Academy.

Appleton left for Notre Dame Academy (NDA) in 2011 where he played alongside his cousin Collin for the Tritons.

[3] During that season, he helped the Tritons win their first state championship after scoring the game-winning goal during the second overtime against Wausau West.

[4] The following year, Appleton helped the NDA Tritons dominate Wisconsin high school hockey by winning their first 20 games before tying Green Bay United.

[7] He played one season of junior ice hockey with the Tri-City Storm before joining the Michigan State Spartans in 2015.

[3] Appleton joined the Michigan State Spartans for their 2015–16 season where he recorded a team-high 17 assists and a total of 22 points in 37 games.

[1] At the conclusion of the 2016–17 season, Appleton was named Team MVP and Outstanding Offensive Player after finishing with a career-best 31 points.

[14] After two seasons with the Spartans, Appleton left college to sign a three-year entry level contract with the Jets with an average annual value of $758,333.

[21] However, as the Moose qualified for the 2018 Calder Cup playoffs, Appleton suffered a concussion and was forced to sit out for their first round matchup with the Grand Rapids Griffins.