Teenage opening batsman Max Holden has signed a four-year deal with Middlesex, which will begin in January 2016.
The 17-year-old left-hander is yet to make his first-team debut for the Lord's side but he has represented England at under-19 level.
"Everybody at the club is very excited about his potential," managing director of cricket Angus Fraser said.
"He is a smashing lad with a great work ethic and we all believe he has a bright future in the game."
Holden has been selected in the England Under-19 squad for their winter tour to Sri Lanka, where they will play Sri Lanka and India in a tri-series.
He will play for Middlesex after completing his A-levels early next summer.