| 2026-10-22 | B. Williams | Hull City → Rotherham | Free agent |
| 2026-10-04 | J. Thornton | Rotherham → Rotherham | - |
| 2026-09-27 | J. Clarke | Ossett United → Rotherham | Return from loan |
| 2026-09-01 | A. Martha | Rotherham → Telstar | Loan |
| 2026-09-01 | George Sebine | Huddersfield → Rotherham | Loan |
| 2026-08-31 | K. Lolos | Peterborough → Rotherham | Loan |
| 2026-08-31 | D. Iorfa | Sheffield Wednesday → Rotherham | Transfer |
| 2026-08-30 | J. Clarke | Rotherham → Ossett United | Loan |
| 2026-08-30 | D. Iorfa | Sheffield Wednesday → Rotherham | Transfer |
| 2026-08-30 | Jayce Fitzgerald | Manchester United (U21) → Rotherham | Loan |
| 2026-08-26 | J. Austerfield | Salford City → Rotherham | Transfer |
| 2026-08-25 | J. Austerfield | Salford City → Rotherham | Transfer |
| 2026-08-23 | R. James | Rotherham → Sheffield Wednesday | Free agent |
| 2026-08-22 | R. James | Rotherham → Sheffield Wednesday | Free agent |
| 2026-08-13 | Dean Gardner | Rotherham → Matlock Town | Loan |
| 2026-08-12 | C. Dawson | Rotherham → Bradford | Free agent |
| 2026-08-10 | J. Eyestone | Brentford → Rotherham | Loan |
| 2026-08-06 | Sonny Aljofree | Manchester United → Rotherham | Free agent |
| 2026-08-05 | Sonny Aljofree | Manchester United → Rotherham | Free agent |
| 2026-08-04 | T. Bradshaw | Oxford United → Rotherham | Free agent |
| 2026-08-04 | K. Ngwenya | Dunfermline → Rotherham | Free agent |
| 2026-08-03 | T. Bradshaw | Oxford United → Rotherham | Free agent |
| 2026-08-03 | E. Otoo | Dunfermline → Rotherham | Free agent |
| 2026-07-28 | P. Mullin | Wrexham → Rotherham | Free agent |
| 2026-07-27 | J. Buyabu | Sheffield Utd → Rotherham | Loan |
| 2026-07-27 | P. Mullin | Wrexham → Rotherham | Free agent |
| 2026-07-23 | S. Nombe | Rotherham → Milton Keynes Dons | Transfer |
| 2026-07-22 | S. Nombe | Rotherham → Milton Keynes Dons | Transfer |
| 2026-07-21 | Ben Hatton | Rotherham → Worksop Town | Free agent |
| 2026-07-16 | S. McWilliams | Rotherham → Cheltenham | Free agent |
| 2026-07-12 | D. Yearwood | Rotherham → Chaves | Free agent |
| 2026-07-09 | O. Ashley | Salford City → Rotherham | Free agent |
| 2026-07-09 | Jamie Jellis | Walsall → Rotherham | Free agent |
| 2026-07-08 | O. Ashley | Salford City → Rotherham | Free agent |
| 2026-07-08 | Jamie Jellis | Walsall → Rotherham | Free agent |
| 2026-07-07 | D. Watmore | Rotherham → Watmore Duncan | End of career |
| 2026-07-06 | Z. Jules | Rotherham → Eyüpspor | Free agent |
| 2026-07-06 | A. Nemane | Milton Keynes Dons → Rotherham | Free agent |
| 2026-07-05 | Z. Jules | Rotherham → Eyüpspor | Free agent |
| 2026-07-05 | A. Nemane | Milton Keynes Dons → Rotherham | Free agent |
| 2026-06-30 | Josh Ayres | Rotherham → Woking | Free agent |
| 2026-06-30 | J. Hugill | Rotherham → Hartlepool | Free agent |
| 2026-06-30 | J. Powell | Rotherham → Salford City | Free agent |
| 2026-06-30 | S. Raggett | Rotherham → Colchester | Free agent |
| 2026-06-30 | A. Ramsell | Rotherham → Rotherham | - |
| 2026-06-30 | Fábio Tavares | Burton Albion → Rotherham | Free agent |
| 2026-06-30 | H. Seisay | Rotherham → East Fife | Free agent |
| 2026-06-30 | J. Holmes | Rotherham → Boston United | Free agent |
| 2026-06-29 | Josh Ayres | Rotherham → Woking | Free agent |
| 2026-06-29 | S. McWilliams | Rotherham → McWilliams Shaun | Free agent |
| 2026-06-29 | S. McWilliams | Rotherham → Cheltenham | Free agent |
| 2026-06-29 | D. Yearwood | Rotherham → Yearwood Dru | Free agent |
| 2026-06-29 | D. Yearwood | Rotherham → Chaves | Free agent |
| 2026-06-29 | J. Baptiste | Rotherham → Sheffield Utd | Return from loan |
| 2026-06-29 | Fábio Tavares | Burton Albion → Rotherham | Free agent |
| 2026-06-29 | K. Ngwenya | Dunfermline → Rotherham | Free agent |
| 2026-06-29 | E. Otoo | Dunfermline → Rotherham | Free agent |
| 2026-06-29 | M. Truswell | Rotherham → Truswell Max | Free agent |
| 2026-06-29 | H. Tchekwa | Rotherham → Tchekwa Harry | Free agent |
| 2026-06-29 | Louis Bassett | Rotherham → Bassett Louis | Free agent |
| 2026-06-09 | C. McGuckin | Rotherham → Harrogate Town | Transfer |
| 2026-05-30 | S. Raggett | Cambridge United → Rotherham | Return from loan |
| 2026-05-30 | L. Sousa | Rotherham → Aston Villa | Return from loan |
| 2026-05-30 | H. Gray | Rotherham → Leeds | Return from loan |
| 2026-05-02 | Daniel Gore | Rotherham → Manchester United | Return from loan |
| 2026-05-02 | Gabriele Biancheri | Rotherham → Biancheri Gabriele | Return from loan |
| 2026-05-02 | Gabriele Biancheri | Rotherham → Manchester United (U21) | Return from loan |
| 2026-03-31 | B. Childs | Rotherham → Rotherham | - |
| 2026-03-17 | Josh Ayres | Alfreton Town → Rotherham | Return from loan |
| 2026-03-06 | Ben Hatton | North Ferriby → Rotherham | Return from loan |
| 2026-02-28 | T. Blackett | Rotherham → New Mexico United | Free agent |
| 2026-02-05 | Ben Hatton | Rotherham → North Ferriby | Loan |
| 2026-02-01 | S. Raggett | Rotherham → Cambridge United | Loan |
| 2026-02-01 | Gabriele Biancheri | Rotherham → Rotherham | Loan |
| 2026-02-01 | Gabriele Biancheri | Manchester United (U21) → Rotherham | Loan |
| 2026-02-01 | Brandon Ashley Cover | Leicester → Rotherham | Transfer |
| 2026-02-01 | L. Sousa | Aston Villa → Rotherham | Loan |
| 2026-02-01 | D. Watmore | Millwall → Rotherham | Free agent |
| 2026-01-22 | E. Adegboyega | Norwich → Rotherham | Transfer |
| 2026-01-21 | Josh Ayres | Rotherham → Alfreton Town | Loan |
| 2026-01-14 | K. Etete | Rotherham → Cardiff | Return from loan |
| 2026-01-13 | H. Gray | Leeds → Rotherham | Loan |
| 2026-01-11 | T. Holmes | Rotherham → Luton | Return from loan |
| 2026-01-01 | C. McGuckin | Eastleigh → Rotherham | Return from loan |
1T. CannGoalkeeper · 25
31B. ChildsGoalkeeper · 17
13J. EyestoneGoalkeeper · 19
16E. AdegboyegaDefender · 22
18L. AgbaireDefender · 20
14Sonny AljofreeDefender · 21
24J. BuyabuAttacker · 22
26H. DouglasMidfielder · 20
36Harrison DuncanDefender · 17
12D. HallDefender · 24
27D. IorfaDefender · 30
5K. NgwenyaDefender · 23
3E. OtooDefender · 23
2J. RaffertyDefender · 32
33B. WilliamsDefender · 25
6O. AshleyMidfielder · 25
4J. AusterfieldMidfielder · 24
37J. ClarkeMidfielder · 19
40L. ClarkeMidfielder
28Brandon Ashley CoverDefender · 22
15Jayce FitzgeraldMidfielder · 18
22Jamie JellisMidfielder · 24
17Marvin Marvellous KaletaMidfielder · 21
51Cohen LeeMidfielder · 19
38Kane RichardsonMidfielder · 18
8K. SpenceMidfielder · 24
9T. BradshawAttacker · 33
20K. LolosAttacker · 25
10P. MullinAttacker · 31
23A. NemaneMidfielder · 28
19George SebineAttacker · 19
7Fábio TavaresAttacker · 24