The 26-year-old, who spent part of last season on loan at the Matchroom Stadium, has signed a two-year contract with the club.
"We're delighted to get Shaun signed up," manager Russell Slade told Orient's official website.
"He made a great impact when he came on loan with us and we wanted to keep him longer than we could do in the end."
Batt scored three goals in 13 games for Orient last campaign.
Restore Data
| Team | P | W | D | L | F | A | GD | PTS | |
| 1 | Birmingham CityBirmingham | 9 | 7 | 1 | 1 | 17 | 9 | 8 | 22 |
| 2 | Wrexham | 10 | 6 | 2 | 2 | 18 | 8 | 10 | 20 |
| 3 | Mansfield TownMansfield | 9 | 6 | 2 | 1 | 17 | 11 | 6 | 20 |
| 4 | Lincoln CityLincoln | 9 | 5 | 3 | 1 | 15 | 8 | 7 | 18 |
| 5 | Wycombe WanderersWycombe | 9 | 5 | 2 | 2 | 17 | 13 | 4 | 17 |
| 6 | Stockport CountyStockport | 9 | 4 | 4 | 1 | 13 | 7 | 6 | 16 |
| 7 | Exeter CityExeter | 9 | 5 | 1 | 3 | 10 | 6 | 4 | 16 |
| 8 | Charlton AthleticCharlton | 10 | 5 | 1 | 4 | 10 | 9 | 1 | 16 |
| 9 | Huddersfield TownHuddersfield | 10 | 5 | 0 | 5 | 14 | 11 | 3 | 15 |
| 10 | Blackpool | 10 | 4 | 3 | 3 | 17 | 16 | 1 | 15 |
| 11 | Barnsley | 10 | 4 | 3 | 3 | 15 | 15 | 0 | 15 |
| 12 | Stevenage | 10 | 4 | 2 | 4 | 8 | 7 | 1 | 14 |
| 13 | Bolton WanderersBolton | 9 | 4 | 2 | 3 | 15 | 15 | 0 | 14 |
| 14 | Peterborough UnitedPeterborough | 10 | 4 | 2 | 4 | 16 | 18 | -2 | 14 |
| 15 | Wigan AthleticWigan | 10 | 3 | 4 | 3 | 9 | 5 | 4 | 13 |
| 16 | Reading | 9 | 4 | 1 | 4 | 13 | 14 | -1 | 13 |
| 17 | Rotherham UnitedRotherham | 10 | 3 | 4 | 3 | 9 | 11 | -2 | 13 |
| 18 | Bristol Rovers | 10 | 4 | 1 | 5 | 13 | 16 | -3 | 13 |
| 19 | Leyton Orient | 10 | 2 | 2 | 6 | 10 | 14 | -4 | 8 |
| 20 | Northampton TownNorthampton | 9 | 2 | 2 | 5 | 11 | 17 | -6 | 8 |
| 21 | Crawley TownCrawley | 9 | 2 | 1 | 6 | 5 | 13 | -8 | 7 |
| 22 | Shrewsbury TownShrewsbury | 10 | 1 | 2 | 7 | 8 | 17 | -9 | 5 |
| 23 | Burton Albion | 9 | 0 | 4 | 5 | 10 | 19 | -9 | 4 |
| 24 | Cambridge UnitedCambridge | 9 | 0 | 1 | 8 | 6 | 17 | -11 | 1 |
| > League One Full Table | |||||||||
