| Competition: | League of Ireland First Division |
| Season: | 2015 |
| Winners: | Wexford Youths |
| Promoted: | Finn Harps |
| League Topscorer: | Daniel Furlong: 30 (Wexford Youths)[1] |
| Prevseason: | 2014 |
| Nextseason: | 2016 |
The 2015 League of Ireland First Division season was the 31st season of the League of Ireland First Division. The First Division was contested by eight teams. Wexford Youths won the title and Finn Harps were also promoted after winning a play off.
Note: Flags indicate national team as has been defined under FIFA eligibility rules. Players may hold more than one non-FIFA nationality.
| Team | Manager | Captain | Kit manufacturer | Shirt sponsor |
|---|---|---|---|---|
| Athlone Town |  Eddie Wallace Alan Mathews | Brian Shortall | Nike | Nitro Sports |
| Cabinteely | Eddie Gormley | Umbro | ||
| Cobh Ramblers | Martin Cambridge Stephen Henderson | Nike | Eirgrid | |
| Finn Harps | Ollie Horgan | Kevin McHugh | Legea | McGettigan Group |
| Shelbourne | Kevin Doherty (footballer) | Macron | ||
| UCD | Collie O'Neill | Robbie Benson | O'Neills | O'Neills |
| Waterford United | Tommy Griffin Roddy Collins | Vinny Sullivan | Macron | SportsWorld |
| Wexford Youths | Shane Keegan | Graham Doyle | O'Neills | Galenisys |
The 2015 First Division featured eight teams. Each team played each other four times, twice at home and twice away, for a total of 28 matches during the season.[2] Wexford Youths secured their first League of Ireland First Division title and promotion to the Premier Division with a 3–0 victory against Athlone Town at Ferrycarrig Park. The Youths goals came from Danny Furlong, Eric Molloy and Aidan Keenan.[3]
| Rank | Player | Club | Goals | |
|---|---|---|---|---|
| 1 | Daniel Furlong | Wexford Youths | 30 | |
| 2 | Ryan Swan | UCD | 12 | |
| 3 | Philip Gorman | Athlone Town | 10 | |
| 4 | Kevin McHugh | Finn Harps | 9 |
The second and third placed First Division teams, Finn Harps and UCD, played off to decide who would play Limerick, the eleventh placed team from the Premier Division. The winner of this play off would play in the 2016 Premier Division.[2]