| 31 Aug 18 | N. Sahin Nuri Sahin |  Borussia DortmundDOR | → |  Werder BremenWER | Undisclosed |
| 31 Aug 18 | R. Bürki Roman Bürki | Borussia DortmundDOR | → | Werder BremenWER | Undisclosed |
| 28 Aug 18 | P. Alcácer Paco Alcácer |  BarcelonaBAR | → | Borussia DortmundDOR | Loan |
| 28 Aug 18 | P. Alcácer Paco Alcácer | BarcelonaBAR | → | Borussia DortmundDOR | Loan |
| 06 Aug 18 | A. Witsel Axel Witsel |  Tianjin QuanjianTIA | → | Borussia DortmundDOR | Undisclosed |
| 25 Jul 18 | A. Schürrle André Schürrle | Borussia DortmundDOR | → |  FulhamFUL | Loan |
| 25 Jul 18 | A. Schürrle André Schürrle | Borussia DortmundDOR | → | FulhamFUL | Loan |
| 13 Jul 18 | E. Durm Erik Durm | Borussia DortmundDOR | → |  Huddersfield TownHUD | Undisclosed |
| 13 Jul 18 | E. Durm Erik Durm | Borussia DortmundDOR | → | Huddersfield TownHUD | Undisclosed |
| 11 Jul 18 | A. Yarmolenko Andriy Yarmolenko | Borussia DortmundDOR | → |  West Ham UnitedWHU | Undisclosed |
| 11 Jul 18 | A. Hakimi Achraf Hakimi |  Real MadridMAD | → | Borussia DortmundDOR | Loan |
| 11 Jul 18 | A. Yarmolenko Andriy Yarmolenko | Borussia DortmundDOR | → | West Ham UnitedWHU | Undisclosed |
| 11 Jul 18 | A. Hakimi Achraf Hakimi | Real MadridMAD | → | Borussia DortmundDOR | Loan |
| 04 Jul 18 | J. Beste Jan-Niklas Beste | Borussia DortmundDOR | → | Werder BremenWER | Undisclosed |
| 02 Jul 18 | F. Passlack Felix Passlack | Borussia DortmundDOR | → |  Norwich CityNOR | Loan |
| 02 Jul 18 | S. Papastathopoulos Sokratis Papastathopoulos | Borussia DortmundDOR | → |  ArsenalARS | Undisclosed |
| 02 Jul 18 | F. Passlack Felix Passlack | Borussia DortmundDOR | → | Norwich CityNOR | Loan |
| 02 Jul 18 | S. Papastathopoulos Sokratis Papastathopoulos | Borussia DortmundDOR | → | ArsenalARS | Undisclosed |
| 01 Jul 18 | M. Hitz Marwin Hitz |  FC AugsburgAUG | → | Borussia DortmundDOR | Free |
| 01 Jul 18 | D. Reimann Dominik Reimann | Borussia DortmundDOR | → |  Holstein KielHOL | Free |
| 01 Jul 18 | E. Oelschlägel Eric Oelschlägel | Werder BremenWER | → | Borussia DortmundDOR | Free |
| 01 Jul 18 | M. Wolf Marius Wolf |  Eintracht FrankfurtSGE | → | Borussia DortmundDOR | 5000000 |
| 01 Jul 18 | G. Castro Gonzalo Castro | Borussia DortmundDOR | → |  VfB StuttgartVFB | Undisclosed |
| 01 Jul 18 | T. Delaney Thomas Delaney | Werder BremenWER | → | Borussia DortmundDOR | Undisclosed |
| 01 Jul 18 | A. Diallo Abdou Diallo |  MainzMAIN | → | Borussia DortmundDOR | Undisclosed |
| 01 Jul 18 | D. Kopacz David Kopacz | Borussia DortmundDOR | → | VfB StuttgartVFB | Undisclosed |
| 07 Jun 18 | T. Delaney Thomas Delaney | Werder BremenWER | → | Borussia DortmundDOR | Undisclosed |
| 31 Jan 18 | P. Aubameyang Pierre-Emerick Aubameyang | Borussia DortmundDOR | → | ArsenalARS | 56000000 |
| 31 Jan 18 | M. Batshuayi Michy Batshuayi |  ChelseaCHE | → | Borussia DortmundDOR | Loan |
| 31 Jan 18 | P. Aubameyang Pierre-Emerick Aubameyang | Borussia DortmundDOR | → | ArsenalARS | 56000000 |
| 31 Jan 18 | M. Batshuayi Michy Batshuayi | ChelseaCHE | → | Borussia DortmundDOR | Loan |
| 30 Jan 18 | S. Gómez Sergio Gómez | BarcelonaBAR | → | Borussia DortmundDOR | Undisclosed |
| 30 Jan 18 | M. Bartra Marc Bartra | Borussia DortmundDOR | → |  Real BetisBET | Undisclosed |
| 30 Jan 18 | S. Gómez Sergio Gómez | BarcelonaBAR | → | Borussia DortmundDOR | Undisclosed |
| 30 Jan 18 | M. Bartra Marc Bartra | Borussia DortmundDOR | → | Real BetisBET | Undisclosed |
| 26 Jan 18 | J. Bruun Larsen Jacob Bruun Larsen | Borussia DortmundDOR | → | VfB StuttgartVFB | Loan |
| 25 Jan 18 | N. Subotic Neven Subotic | Borussia DortmundDOR | → |  Saint-EtienneASSE | Undisclosed |
| 25 Jan 18 | N. Subotic Neven Subotic | Borussia DortmundDOR | → | Saint-EtienneASSE | Undisclosed |
| 15 Jan 18 | M. Akanji Manuel Akanji |  FC BaselBAS | → | Borussia DortmundDOR | Undisclosed |
| 01 Jan 18 | M. Merino Mikel Merino | Borussia DortmundDOR | → |  Newcastle UnitedNEW | Undisclosed |
| 01 Jan 18 | M. Merino Mikel Merino | Borussia DortmundDOR | → | Newcastle UnitedNEW | Undisclosed |