St Mirren have confirmed Dylan Reid has joined Crystal Palace for an undisclosed fee "with significant add-ons and a potential sell-on".
The midfielder, 17, was due to be out of contract this summer and has signed a three-and-a-half-year deal with the Premier League side.
Reid became St Mirren's - and the Scottish Premiership's - youngest player with a debut against Rangers in March 2021 at 16 years and five days.
He has played eight first-team games.
Reid will be part of Palace's academy set-up and told the London club's website: "I can't wait to see where this will go.