Young will link up with the Black Caps' for training on Monday ahead of the second Test of the three-match series that starts at the Oval on Wednesday.
New Zealand legend Williamson called time on his international career with immediate effect after scoring 0 and 18 in the first Test defeat at Lord's.
Williamson said: "I've thought about it for a while, but over the last few days it's become clear now is the right time.
"I've always felt a strong drive and hunger for international cricket, and I take pride in knowing I've given it my all in every match I've played for New Zealand. Continuing with anything less wouldn't be right and I feel fortunate to step away on my own terms.
"I leave feeling optimistic about where this group is heading. There's a huge amount of talent, and a real desire to do something special with this New Zealand team.
"It's a team I love, and I feel incredibly fortunate to have been part of it for so long. It will continue to be dear to my heart."
Henry Nicholls was the reserve batter in the squad for the Lord's Test and is set to replace Williamson in the starting XI.
New Zealand legend Kane Williamson has called time on his international career with immediate effect, leaving the highest stage as his country's leading run-scorer in Test cricket.
England launched their post-Ashes rebuild in emphatic fashion with a 115-run victory over New Zealand in the first Test at Lord's, wrapping up the win before lunch on the fourth day after a brutal, seam-dominated contest.
England moved closer to victory over New Zealand after a rain-hit third day of the first Test at Lord’s, which saw just 10 overs of play possible.
New Zealand will need another 218 runs to win the first Test against England but the hosts need seven wickets for victory after a late double-strike at the end of the second day at Lord's.
