The 21-year-old scored 11 goals during his spell with the club last season, while he is yet to make his competitive league debut for Wolves.
The Scot becomes Hibs boss Pat Fenlon's fifth signing of the summer as they prepare for the new campaign.
Griffiths will join up with the squad at their pre-season base in Holland on Saturday.
Restore Data
| Team | P | W | D | L | F | A | GD | PTS | |
| 1 | Liverpool | 14 | 11 | 2 | 1 | 29 | 11 | 18 | 35 |
| 2 | Chelsea | 15 | 9 | 4 | 2 | 35 | 18 | 17 | 31 |
| 3 | Arsenal | 15 | 8 | 5 | 2 | 29 | 15 | 14 | 29 |
| 4 | Manchester CityMan City | 15 | 8 | 3 | 4 | 27 | 21 | 6 | 27 |
| 5 | Nottingham ForestNott'm Forest | 15 | 7 | 4 | 4 | 19 | 18 | 1 | 25 |
| 6 | Aston Villa | 15 | 7 | 4 | 4 | 23 | 23 | 0 | 25 |
| 7 | Brighton & Hove AlbionBrighton | 15 | 6 | 6 | 3 | 25 | 22 | 3 | 24 |
| 8 | Bournemouth | 15 | 7 | 3 | 5 | 23 | 20 | 3 | 24 |
| 9 | Brentford | 15 | 7 | 2 | 6 | 31 | 28 | 3 | 23 |
| 10 | Fulham | 15 | 6 | 5 | 4 | 22 | 20 | 2 | 23 |
| 11 | Tottenham HotspurSpurs | 15 | 6 | 2 | 7 | 31 | 19 | 12 | 20 |
| 12 | Newcastle UnitedNewcastle | 15 | 5 | 5 | 5 | 19 | 21 | -2 | 20 |
| 13 | Manchester UnitedMan Utd | 15 | 5 | 4 | 6 | 19 | 18 | 1 | 19 |
| 14 | West Ham UnitedWest Ham | 15 | 5 | 3 | 7 | 20 | 28 | -8 | 18 |
| 15 | Everton | 14 | 3 | 5 | 6 | 14 | 21 | -7 | 14 |
| 16 | Leicester CityLeicester | 15 | 3 | 5 | 7 | 21 | 30 | -9 | 14 |
| 17 | Crystal Palace | 15 | 2 | 7 | 6 | 14 | 20 | -6 | 13 |
| 18 | Ipswich TownIpswich | 15 | 1 | 6 | 8 | 14 | 27 | -13 | 9 |
| 19 | Wolverhampton WanderersWolves | 15 | 2 | 3 | 10 | 23 | 38 | -15 | 9 |
| 20 | Southampton | 15 | 1 | 2 | 12 | 11 | 31 | -20 | 5 |
| > Premier League Full Table | |||||||||
