| july 31 2018 |  J. Mamontovas |  Rotherham City #3 | Sunderland #5 | RSD2 799 626 |
| july 30 2018 |  R. Scheffler | Rotherham City #3 |  Compton FC | RSD2 179 067 |
| july 30 2018 |  J. Šumelis | Rotherham City #3 |  Maha United | RSD1 700 192 |
| july 29 2018 | T. Worthington | Rotherham City #3 | None | Player is fired |
| july 5 2018 |  M. Aïni | Blackpool #6 | Rotherham City #3 | RSD8 010 000 |
| july 4 2018 |  D. Curado | Exeter City #5 | Rotherham City #3 | RSD4 820 400 |
| july 3 2018 |  A. Lauga | Rotherham City #3 |  Athletic Club Milano 1983 | RSD1 557 600 |
| july 3 2018 |  O. Mobutu | NewCastle FC | Rotherham City #3 (On loan) | (RSD90 000) |
| july 2 2018 | J. Šumelis | Rotherham City #3 |  Kilkenny | Reverted |
| july 2 2018 | R. Scheffler | Rotherham City #3 | Kilkenny | Reverted |
| july 1 2018 |  M. Cheung | Stoke United #2 | Rotherham City #3 | RSD6 493 500 |
| june 8 2018 |  P. Minh Danh |  FC Port Talbot | Rotherham City #3 | RSD6 447 000 |
| may 16 2018 |  V. Toptani |  Mystic Warrior Copenhagen | Rotherham City #3 (On loan) | (RSD577 500) |
| may 12 2018 | L. Acum | Burton upon Trent City | Rotherham City #3 (On loan) | (RSD400 500) |
| may 12 2018 | S. Carrard |  Carten Isle Rangers | Rotherham City #3 | RSD7 372 080 |
| may 11 2018 | G. Tornas | Rotherham City #3 |  Serbian Dark Force FC | RSD133 125 |
| april 18 2018 | S. Pauli | Dublin #20 | Rotherham City #3 | RSD2 638 500 |
| march 28 2018 |  W. Tuiahi |  FC Tartu #3 | Rotherham City #3 (On loan) | (RSD567 000) |
| march 25 2018 | A. Šalčius | Rotherham City #3 |  FC Les Abymes #4 | RSD3 933 750 |
| march 25 2018 |  C. Olah | Canvey Pixels | Rotherham City #3 (On loan) | (RSD300 000) |
| march 24 2018 | P. Cech | FC Tromsø #2 | Rotherham City #3 (On loan) | (RSD1 676 028) |
| march 22 2018 | F. Hayday | Rotherham City #3 |  Wroclaw #4 | RSD336 000 |
| march 19 2018 |  H. Fuentiduena |  au p'tit bonheur | Rotherham City #3 | RSD12 238 500 |
| february 2 2018 |  R. Emukhvarov | Fana | Rotherham City #3 (On loan) | (RSD331 500) |
| january 30 2018 |  A. Brauner | Ludvika FF | Rotherham City #3 (On loan) | (RSD216 000) |
