During his early days, the one-time Manchester United shot-stopper gained experience from ten separate loans across League One and the Championship, including two stints at Aston Villa between 2016 and 2018.
Johnstone became a regular No.1 one for the first time when he joined West Bromwich Albion, playing every minute as the Baggies won promotion and securing him a first taste of the Premier League, where he was voted Player of the Season, despite a quick return to the second tier.
It was while at the Hawthorns the stopper earned a first senior England cap, having previously won the Under-17 Euros in 2010, and he was part of the senior Three Lions squad which reached the final of Euro 2020 at Wembley.
Johnstone’s past two seasons have been spent at Selhurst Park and last year he was an Eagles regular either side of calf and elbow injuries, which kept him sidelined for two spells and denied him a place at Euro 2024.
Having been on the bench for Palace so far this season, he’s signed a long-term deal at Molineux, which includes the option of a further 12 months.
The Wolves Sporting director Matt Hobbs said: “It's great for us to have a player with a huge amount of Premier League experience and an international goalkeeper. It’s an area of the pitch we wanted to add more competition and, for us, it's finding the right balance between the level of investment, what it adds to the squad and what it enables us to do for the rest of the squad."
“Sam’s at a good age – goalkeepers come into their prime a bit later – and what happens from here will be up to the boys in the building, but adding someone like him is valuable for us.
“People know that we’re looking for good characters and we're not going to take someone who is a really good player but doesn’t fit culturally. He ticks a lot of boxes and it’s up to him and the others to fight out for that position," he added.