| 28 Aug 18 | D. Mitchell Demetri Mitchell |  Manchester UnitedMAN | → |  Heart of MidlothianHOM | Loan |
| 28 Aug 18 | D. Mitchell Demetri Mitchell | Manchester UnitedMAN | → | Heart of MidlothianHOM | Loan |
| 15 Aug 18 | K. O'Hara Kieran O'Hara | Manchester UnitedMAN | → |  Macclesfield TownMACC | Loan |
| 13 Aug 18 | J. Wilson James Wilson | Manchester UnitedMAN | → |  AberdeenABER | Loan |
| 13 Aug 18 | J. Wilson James Wilson | Manchester UnitedMAN | → | AberdeenABER | Loan |
| 09 Aug 18 | T. Fosu-Mensah Timothy Fosu-Mensah | Manchester UnitedMAN | → |  FulhamFUL | Loan |
| 06 Aug 18 | A. Tuanzebe Axel Tuanzebe | Manchester UnitedMAN | → |  Aston VillaAVL | Loan |
| 06 Aug 18 | A. Tuanzebe Axel Tuanzebe | Manchester UnitedMAN | → | Aston VillaAVL | Loan |
| 02 Aug 18 | J. Pereira Joel Pereira | Manchester UnitedMAN | → |  Vitoria SetubalSET | Loan |
| 01 Aug 18 | Tosin Kehinde | Manchester UnitedMAN | → |  FeirenseFEI | Free |
| 28 Jul 18 | M. Willock Matthew Willock | Manchester UnitedMAN | → |  St MirrenSTM | Loan |
| 28 Jul 18 | M. Willock Matthew Willock | Manchester UnitedMAN | → | St MirrenSTM | Loan |
| 28 Jul 18 | C. Borthwick-Jackson Cameron Borthwick-Jackson | Manchester UnitedMAN | → |  Scunthorpe UnitedSCU | Loan |
| 17 Jul 18 | D. Blind Daley Blind | Manchester UnitedMAN | → |  Ajax AmsterdamAJA | Undisclosed |
| 17 Jul 18 | D. Blind Daley Blind | Manchester UnitedMAN | → | Ajax AmsterdamAJA | Undisclosed |
| 03 Jul 18 | L. Grant Lee Grant |  Stoke CitySTK | → | Manchester UnitedMAN | Undisclosed |
| 03 Jul 18 | S. Johnstone Sam Johnstone | Manchester UnitedMAN | → |  West Bromwich AlbionWBA | Undisclosed |
| 03 Jul 18 | L. Grant Lee Grant | Stoke CitySTK | → | Manchester UnitedMAN | Undisclosed |
| 03 Jul 18 | S. Johnstone Sam Johnstone | Manchester UnitedMAN | → | West Bromwich AlbionWBA | Undisclosed |
| 01 Jul 18 | D. Henderson Dean Henderson | Manchester UnitedMAN | → |  Sheffield UnitedSHU | Loan |
| 01 Jul 18 | D. Henderson Dean Henderson | Manchester UnitedMAN | → | Sheffield UnitedSHU | Loan |
| 21 Jun 18 | Fred | SDXShakhtar DonetskShakhtar Donetsk | → | Manchester UnitedMAN | Undisclosed |
| 08 Jun 18 | D. Dalot Diogo Dalot |  FC PortoPOR | → | Manchester UnitedMAN | Undisclosed |
| 25 May 18 | Joe Riley | Manchester UnitedMAN | → |  Bradford CityBRD | Undisclosed |
| 23 Mar 18 | Z. Ibrahimovic Zlatan Ibrahimovic | Manchester UnitedMAN | → |  LA GalaxyLA | Free |
| 23 Mar 18 | Z. Ibrahimovic Zlatan Ibrahimovic | Manchester UnitedMAN | → | LA GalaxyLA | Free |
| 31 Jan 18 | Matej Kovar | FSXFC SlovackoFC Slovacko | → | Manchester UnitedMAN | Undisclosed |
| 31 Jan 18 | M. Willock Matthew Willock | Manchester UnitedMAN | → |  St JohnstoneSTJO | Loan |
| 31 Jan 18 | M. Willock Matthew Willock | Manchester UnitedMAN | → | St JohnstoneSTJO | Loan |
| 29 Jan 18 | A. Smith-Brown Ashley Smith-Brown | Manchester UnitedMAN | → |  Oxford UnitedOXF | Loan |
| 25 Jan 18 | A. Tuanzebe Axel Tuanzebe | Manchester UnitedMAN | → | Aston VillaAVL | Loan |
| 25 Jan 18 | A. Tuanzebe Axel Tuanzebe | Manchester UnitedMAN | → | Aston VillaAVL | Loan |
| 22 Jan 18 | A. Sánchez Alexis Sánchez |  ArsenalARS | → | Manchester UnitedMAN | Swap |
| 22 Jan 18 | H. Mkhitaryan Henrikh Mkhitaryan | Manchester UnitedMAN | → | ArsenalARS | Swap |
| 11 Jan 18 | D. Mitchell Demetri Mitchell | Manchester UnitedMAN | → | Heart of MidlothianHOM | Loan |
| 11 Jan 18 | D. Mitchell Demetri Mitchell | Manchester UnitedMAN | → | Heart of MidlothianHOM | Loan |
| 10 Jan 18 | J. Wilson James Wilson | Manchester UnitedMAN | → | Sheffield UnitedSHU | Loan |
| 10 Jan 18 | J. Wilson James Wilson | Manchester UnitedMAN | → | Sheffield UnitedSHU | Loan |