Strike pairing Britt Assombalonga and Ashley Fletcher - told back in April that they were free to leave the club - head up Boro's list of departures on their retained list, with Johnson, Archer, and Mendez-Laing also told that they will not be offered new contracts when their deals expire at the end of June.
Tyrone O’Neill, who made his first team debut at Leeds in 2019 has also been released, alongside fellow young players Cole Kiernan and Tyler Williams have not been offered new contracts.
Scholars George Waites and Andrew Wilson have also been released.
Boro have already made a close-season capture in the shape of QPR goalkeeper Joe Lumley who will officially sign for the club in July when his Loftus Road contract expires.
Meanwhile, Academy products Jack Robinson, Cain Sykes and Hayden Hackney have signed new contracts, while Josh Wells and Jeremy Sivi have agreed terms after impressing on trial - with Isiah Cornet and Max Metcalfe penning their first professional contracts.