Grant William Millington (born 1 November 1986) is an Australian former professional rugby league footballer, who last played as a prop, second-row or loose forward for the Western Suburbs Red Devils in the Country Rugby League.

He previously played for Castleford Tigers in the Super League and in the NRL for the Cronulla-Sutherland Sharks between 2008 and 2010, and for the Canterbury-Bankstown Bulldogs in 2011.

Millington holds the Castleford club record for most appearances made by an overseas player, accumulating 244 across his 10 seasons with the Tigers. He is widely recognised as one of the club's greatest imports, and is considered a fans' favourite due to his consistency and commitment as well as his community contributions off the pitch. He was utilised as a skilful, ball-handling and intelligent prop/second-row forward and was even called upon to cover in the halves on occasion.

Millington was born in Auburn, New South Wales, Australia.

He played his junior rugby league for the Cabramatta Two Blues and Wyong Roos.

Millington made his first grade debut for Cronulla in round 10 of the 2008 NRL season against Brisbane. Cronulla-Sutherland went on to finish third in 2008 but Millington made no appearances for the club during the finals series.

In the 2009 NRL season, Millington made 17 appearances for Cronulla-Sutherland as they finished 2nd last on the table.

In the 2010 NRL season, Millington played in nearly every game for Cronulla-Sutherland that year as the club finished near the bottom of the ladder.