The 26-year-old has struggled to force his way into Aitor Karanka's side this season, making only one appearance in the Championship.
The Argentine winger will now join up with former teammates Richie Smallwood and Frazer Richardson at New York Stadium until January.
Ledesma, who began his career with Italian side Genoa, joined Middlesbrough from Walsall in 2012.
Restore Data
| Team | P | W | D | L | F | A | GD | PTS | |
| 1 | Birmingham CityBirmingham | 8 | 7 | 1 | 0 | 17 | 8 | 9 | 22 |
| 2 | Wrexham | 9 | 5 | 2 | 2 | 14 | 7 | 7 | 17 |
| 3 | Mansfield TownMansfield | 8 | 5 | 2 | 1 | 15 | 11 | 4 | 17 |
| 4 | Stockport CountyStockport | 8 | 4 | 3 | 1 | 13 | 7 | 6 | 15 |
| 5 | Lincoln CityLincoln | 8 | 4 | 3 | 1 | 13 | 7 | 6 | 15 |
| 6 | Blackpool | 9 | 4 | 3 | 2 | 17 | 14 | 3 | 15 |
| 7 | Huddersfield TownHuddersfield | 10 | 5 | 0 | 5 | 14 | 11 | 3 | 15 |
| 8 | Barnsley | 10 | 4 | 3 | 3 | 15 | 15 | 0 | 15 |
| 9 | Wycombe WanderersWycombe | 8 | 4 | 2 | 2 | 16 | 13 | 3 | 14 |
| 10 | Stevenage | 10 | 4 | 2 | 4 | 8 | 7 | 1 | 14 |
| 11 | Peterborough UnitedPeterborough | 10 | 4 | 2 | 4 | 16 | 18 | -2 | 14 |
| 12 | Exeter CityExeter | 8 | 4 | 1 | 3 | 9 | 6 | 3 | 13 |
| 13 | Bolton WanderersBolton | 8 | 4 | 1 | 3 | 13 | 13 | 0 | 13 |
| 14 | Reading | 8 | 4 | 1 | 3 | 12 | 12 | 0 | 13 |
| 15 | Charlton AthleticCharlton | 9 | 4 | 1 | 4 | 9 | 9 | 0 | 13 |
| 16 | Wigan AthleticWigan | 9 | 3 | 3 | 3 | 9 | 5 | 4 | 12 |
| 17 | Rotherham UnitedRotherham | 9 | 2 | 4 | 3 | 7 | 10 | -3 | 10 |
| 18 | Bristol Rovers | 9 | 3 | 1 | 5 | 10 | 15 | -5 | 10 |
| 19 | Northampton TownNorthampton | 8 | 2 | 2 | 4 | 10 | 13 | -3 | 8 |
| 20 | Leyton Orient | 9 | 2 | 2 | 5 | 9 | 12 | -3 | 8 |
| 21 | Crawley TownCrawley | 8 | 2 | 1 | 5 | 5 | 12 | -7 | 7 |
| 22 | Burton Albion | 8 | 0 | 4 | 4 | 9 | 16 | -7 | 4 |
| 23 | Shrewsbury TownShrewsbury | 9 | 1 | 1 | 7 | 6 | 15 | -9 | 4 |
| 24 | Cambridge UnitedCambridge | 8 | 0 | 1 | 7 | 6 | 16 | -10 | 1 |
| > League One Full Table | |||||||||
