The 25-year-old joined from Oldham Athletic last summer and will now be at Elland Road until the summer of 2017.
"It is a huge honour and a privilege for me to represent the football club," he told the club website.
"To extend my future here is brilliant and I'm over the moon."
Smith scored 13 goals in all competitions in his debut season for the Whites, but he is yet to find the net this season.
Restore Data
| Team | P | W | D | L | F | A | GD | PTS | |
| 1 | Ipswich TownIpswich | 43 | 26 | 11 | 6 | 85 | 53 | 32 | 89 |
| 2 | Leicester CityLeicester | 42 | 28 | 4 | 10 | 79 | 38 | 41 | 88 |
| 3 | Leeds UnitedLeeds | 43 | 26 | 9 | 8 | 76 | 34 | 42 | 87 |
| 4 | Southampton | 42 | 25 | 9 | 8 | 84 | 54 | 30 | 84 |
| 5 | West Bromwich AlbionWest Brom | 43 | 20 | 12 | 11 | 66 | 42 | 24 | 72 |
| 6 | Norwich CityNorwich | 43 | 21 | 8 | 14 | 76 | 60 | 16 | 71 |
| 7 | Hull City | 42 | 18 | 11 | 13 | 62 | 54 | 8 | 65 |
| 8 | Coventry CityCoventry | 42 | 17 | 12 | 13 | 66 | 52 | 14 | 63 |
| 9 | Middlesbrough | 43 | 18 | 9 | 16 | 61 | 56 | 5 | 63 |
| 10 | Preston North EndPreston | 43 | 18 | 9 | 16 | 56 | 60 | -4 | 63 |
| 11 | Cardiff CityCardiff | 43 | 18 | 5 | 20 | 48 | 60 | -12 | 59 |
| 12 | Bristol City | 43 | 16 | 10 | 17 | 50 | 46 | 4 | 58 |
| 13 | Sunderland | 43 | 16 | 8 | 19 | 52 | 50 | 2 | 56 |
| 14 | Swansea CitySwansea | 43 | 14 | 11 | 18 | 53 | 62 | -9 | 53 |
| 15 | Watford | 43 | 12 | 16 | 15 | 59 | 58 | 1 | 52 |
| 16 | Millwall | 43 | 13 | 11 | 19 | 42 | 55 | -13 | 50 |
| 17 | Blackburn RoversBlackburn | 43 | 13 | 10 | 20 | 57 | 71 | -14 | 49 |
| 18 | Plymouth ArgylePlymouth | 43 | 12 | 12 | 19 | 58 | 66 | -8 | 48 |
| 19 | Queens Park RangersQPR | 43 | 12 | 11 | 20 | 40 | 57 | -17 | 47 |
| 20 | Stoke CityStoke | 43 | 12 | 11 | 20 | 41 | 60 | -19 | 47 |
| 21 | Birmingham CityBirmingham | 43 | 12 | 9 | 22 | 48 | 64 | -16 | 45 |
| 22 | Huddersfield TownHuddersfield | 43 | 9 | 17 | 17 | 47 | 70 | -23 | 44 |
| 23 | Sheffield WednesdaySheff Weds | 43 | 12 | 8 | 23 | 36 | 67 | -31 | 44 |
| R | Rotherham UnitedRotherham | 43 | 4 | 11 | 28 | 32 | 85 | -53 | 23 |
| > Championship Full Table | |||||||||
