Smeed has been with Somerset since under-10 age grade and made his debut in 2020, signing professional terms a year later.
He has gone on to make 64 T20 appearances for the club, scoring 1,669 runs including 12 half-centuries and was part of the 2023 Blast-winning side.
In 2022, Smeed became the first batter to hit a century in The Hundred, playing for Birmingham Phoenix.
He has featured in the Pakistan Super League, SA20, Caribbean Premier League and International League T20 but is yet to play in first-class cricket and has only one 50-over game to his name, for England Lions.
Somerset director of cricket Andy Hurry said Smeed’s return will “add depth” to their batting in the four-day game.
“We all know Will has a huge amount of potential, and his return to multi-day cricket will certainly add depth to our County Championship batting options,” Hurry said.
“When he initially signed a white-ball contract, he always made it clear that the door was not closed to the red-ball game, and I know our members and supporters will be excited by the prospect of him now being available to be considered for selection in all formats for the club.”
Somerset start their County Championship season at home to Worcestershire on Friday, 4 April.
