Following the arrivals of Jordan Archer, Yannick Bolasie and Darnell Fisher, Boro added former Cardiff winger Nathaniel Mendez-Laing and Fulham midfielder Neeskens Kebano to their ranks on transfer deadline day.
The Teessiders also allowed Nathan Wood and Lewis Wing to leave the club on loan, while playmaker Patrick Roberts was allowed to cut short his loan spell, allowing the Manchester City man to join Derby for the second half of the campaign.
While there weren’t as many big-money deals compared to previous windows, there were still plenty of moves around the second tier as clubs finalised their squads.
We've taken a look at every deal which was completed in the Championship and how Boro’s rivals fared:
21. Stoke
INS: Rabbi Matondo (FC Schalke 04, loan), Rhys Norrington-Davies (Sheffield United, loan), Jack Clarke (Tottenham, loan), Alfie Doughty (Charlton) OUTS: Kevin Wimmer (loan), Tom Ince (loan), Thibaud Verlinden, Liam Lindsay (loan), Lee Gregory (loan), Tom Edwards (loan) Photo: Gareth Copley
22. Swansea
INS: Ben Hamer (Huddersfield), Conor Hourihane (Aston Villa, loan), Jordan Morris (Seattle Sounders, loan) Morgan Whittaker (Derby), Paul Arriola (DC United, loan), Kieron Freeman (Swindon) OUTS: Declan John (loan), George Byers (loan), Jordan Garric (loan) Photo: David Rogers
23. Watford
INS: Philip Zinckernagel (Bodo/Glimt), Rob Elliot (free), Dan Gosling (Bournemouth), Maurizio Pochettino (Tottenham) OUTS: Etienne Capoue, Gerard Deulofeu, James Garner, Domingos Quina (loan) Photo: Richard Heathcote
![INS: Admiral Muskwe (Leicester, loan), Jordan Obita (Oxford]) OUTS: Giles Phillips (loan)](https://www.worksopguardian.co.uk/webimg/b25lY21zOjVhNjNiMTZlLWNlOGQtNDUzZi1hZWI4LWRjNzlmNzU1YmQ5NTpmMzU2YjcyMy1jZGJmLTQxMDUtYmRmMi05YTdlYjg0YzE0YWM=.jpg?crop=4:3&trim=&width=640)
24. Wycombe
INS: Admiral Muskwe (Leicester, loan), Jordan Obita (Oxford]) OUTS: Giles Phillips (loan) Photo: Catherine Ivill