The National Basketball League Championship Series Most Valuable Player, formerly known as the Grand Final MVP, is an annual National Basketball League (NBL) award given since the league's inaugural season to the best performing player of the Championship Series. The winner receives the Larry Sengstock Medal, which is named in honour of Larry Sengstock, the winner of the league's first Grand Final MVP award. The league named the award after Sengstock in 1999.
Between 1979 and 2022, the single game or series was known as the NBL Grand Final. With the league's change in finals format in 2023, the grand final name was replaced by Championship Series. Derrick Walton of the Sydney Kings won the first Championship Series MVP in 2023. In 2025, Matthew Dellavedova of Melbourne United became just the second player after Ricky Grace in 1993 to win the Championship Series MVP from the losing side.