Hughes became another foundational player for the Devils when he signed a seven-year, $63 million contract Oct. 1, 2025 ($9 million average annual value). He completed his second full NHL season with 44 points (seven goals, 37 assists) in 71 games to lead Devils defensemen.

The native of Manchester, New Hampshire, was named a finalist for the 2024 Calder Trophy given to the NHL rookie of the year after finishing tied for second among rookies with 47 points (nine goals, 38 assists) in 82 games, the second-most points by a first-year defenseman in Devils/Colorado Rockies/Kansas City Scouts history behind Barry Beck's 60 for the Rockies in 1977-78.

Hughes made his NHL debut with two blocked shots, one hit and one takeaway in 11:15 of ice time playing as the seventh defensemen during a 6-2 victory against the Buffalo Sabres at Prudential Center on April 11, 2023 -- the same night older brother and Devils center Jack Hughes set a franchise single-season record of 97 points (43 goals, 54 assists). He scored his first NHL goal with 27 seconds remaining in overtime of a 5-4 win at the Washington Capitals on April 13 and had two assists in his Stanley Cup Playoff debut, an 8-4 win against the Carolina Hurricanes in Game 3 of the 2023 Eastern Conference Second Round. Luke and Jack became the first set of brothers to factor on the same playoff goal since Daniel Sedin and Henrik Sedin for the Vancouver Canucks in Game 6 of the 2015 first round.

Hughes signed a three-year, entry-level contract with the Devils on April 8, two days after the University of Michigan was eliminated from the NCAA Frozen Four with a 5-2 loss to Quinnipiac. The No. 4 pick in the 2021 NHL Draft turned pro after two seasons at Michigan, where he had 87 points (27 goals, 60 assists) in 80 games in two seasons. He had 48 points (10 goals, 38 assists) in 39 games in 2022-23 to help the Wolverines go 26-12-3 and reach the Frozen Four for the second straight season.