The 20-year-old, who signed a three-year deal with the Tykes during the summer, will remain with the Dons until January 5.
Jennings has made just five appearances for Barnsley this season since joining the club from Bayern Munich.
MK Dons, who sit 11th in League One, face Coventry City on Saturday.
Restore Data
| Team | P | W | D | L | F | A | GD | PTS | |
| C | Stockport CountyStockport | 44 | 26 | 11 | 7 | 91 | 44 | 47 | 89 |
| P | Mansfield TownMansfield | 44 | 23 | 13 | 8 | 87 | 45 | 42 | 82 |
| P | Wrexham | 44 | 24 | 10 | 10 | 84 | 51 | 33 | 82 |
| 4 | MK Dons | 44 | 22 | 8 | 14 | 74 | 61 | 13 | 74 |
| 5 | Crewe AlexandraCrewe | 44 | 19 | 13 | 12 | 68 | 61 | 7 | 70 |
| 6 | BarrowBarrow | 43 | 18 | 14 | 11 | 58 | 49 | 9 | 68 |
| 7 | Crawley TownCrawley | 44 | 20 | 6 | 18 | 69 | 65 | 4 | 66 |
| 8 | Walsall | 44 | 18 | 11 | 15 | 66 | 65 | 1 | 65 |
| 9 | Doncaster RoversDoncaster | 43 | 19 | 7 | 17 | 63 | 63 | 0 | 64 |
| 10 | Gillingham | 44 | 18 | 9 | 17 | 43 | 53 | -10 | 63 |
| 11 | AFC Wimbledon | 44 | 16 | 14 | 14 | 57 | 47 | 10 | 62 |
| 12 | Harrogate TownHarrogate | 44 | 17 | 11 | 16 | 55 | 62 | -7 | 62 |
| 13 | Bradford CityBradford | 43 | 16 | 12 | 15 | 52 | 55 | -3 | 60 |
| 14 | Notts County | 44 | 17 | 7 | 20 | 88 | 85 | 3 | 58 |
| 15 | Morecambe | 44 | 17 | 9 | 18 | 63 | 76 | -13 | 57 |
| 16 | Newport CountyNewport | 44 | 16 | 7 | 21 | 61 | 71 | -10 | 55 |
| 17 | Tranmere RoversTranmere | 44 | 16 | 6 | 22 | 63 | 64 | -1 | 54 |
| 18 | Accrington StanleyAccrington | 44 | 15 | 9 | 20 | 57 | 66 | -9 | 54 |
| 19 | Swindon TownSwindon | 44 | 14 | 11 | 19 | 74 | 78 | -4 | 53 |
| 20 | Salford City | 44 | 12 | 11 | 21 | 63 | 80 | -17 | 47 |
| 21 | Grimsby Town | 44 | 10 | 16 | 18 | 55 | 72 | -17 | 46 |
| 22 | Colchester UnitedColchester | 43 | 11 | 11 | 21 | 57 | 74 | -17 | 44 |
| 23 | Sutton UnitedSutton | 44 | 9 | 13 | 22 | 53 | 78 | -25 | 40 |
| R | Forest Green RoversForest Green | 44 | 9 | 9 | 26 | 41 | 77 | -36 | 36 |
| > League Two Full Table | |||||||||
