| Super League IV | |
| League: | Super League |
| Pixels: | 90px |
| Duration: | 30 Rounds |
| No Of Teams: | 14 |
| Highest Attendance: | 24,020 Bradford Bulls vs Leeds Rhinos (3 Sept) |
| Lowest Attendance: | 1,580 Gateshead Thunder vs Hull Sharks (19 May) |
| Tv: | Sky Sports |
| Season: | 1999 Season |
| Season Champs: | St. Helens 2nd Super League title 9th British title |
| Season Champ Name: | Champions |
| League Leaders: | Bradford Bulls |
| League Leaders Name: | League Leaders |
| Mvp Link: | Man of Steel AwardsMan of Steel |
| Top Scorer: | Iestyn Harris (325) |
| Top Try Scorer: |  Toa Kohe-Love (25) |
| Membership Type: | Left League |
| Leave: | Gateshead Thunder |
| Leave Reason: | Merged with Hull FC Merger with Huddersfield Giants |
| Prevseason Link: | Super League III |
| Prevseason Year: | 1998 |
| Nextseason Link: | Super League V |
| Nextseason Year: | 2000 |
JJB Sports Super League IV was the official name for the year 1999's Super League championship season, the 105th season of top-level professional rugby league football in Britain, and the fourth championship run by the Super League. The start of Super League IV saw the emergence of a North East based Rugby League Club, Gateshead Thunder as well as newly promoted Wakefield Trinity Wildcats to expand the league to fourteen teams.
| Legend | ||
|---|---|---|
| Reigning Champions | ||
| Promoted | ||
| Team | Stadium | Capacity | City/Area | ||
|---|---|---|---|---|---|
| Bradford Bulls | Odsal | 27,000 | Bradford, West Yorkshire | ||
| Castleford Tigers | Wheldon Road | 11,750 | Castleford, West Yorkshire | ||
| Gateshead Thunder | Gateshead International Stadium | 11,800 | Gateshead, Tyne and Wear | ||
| Halifax Blue Sox | Thrum Hall | 9,832 | Halifax, West Yorkshire | ||
| Huddersfield Giants | Galpharm Stadium | 24,500 | Huddersfield, West Yorkshire | ||
| Hull Sharks | The Boulevard | 10,500 | Hull, East Riding of Yorkshire | ||
| Leeds Rhinos | Headingley | 21,500 | Leeds, West Yorkshire | ||
| London Broncos | The Valley | 27,000 | Charlton, Greater London | ||
| Salford Reds | The Willows | 11,363 | Salford, Greater Manchester | ||
| Sheffield Eagles | Don Valley Stadium | 25,000 | Sheffield, South Yorkshire | ||
| St. Helens | Knowsley Road | 17,500 | St Helens, Mersyside | ||
| Warrington Wolves | Wilderspool | 9,200 | Warrington, Cheshire | ||
| Wigan Warriors | Central Park | 18,000 | Wigan, Greater Manchester |