| Competition: | League of Ireland |
| Winners: | Shamrock Rovers (8th title) |
| Continentalcup1: | European Cup |
| Continentalcup1 Qualifiers: | Shamrock Rovers |
| Matches: | 132 |
| Total Goals: | 484 |
| League Topscorer: | Tommy Hamilton Donal Leahy (15 goals) |
| Biggest Home Win: | Waterford 10–2 Limerick |
| Biggest Away Win: | Limerick 1–6 Shelbourne F.C. Shelbourne 0–5 Evergreen United |
| Highest Scoring: | Waterford 10–2 Limerick |
| Prevseason: | 1955–56 |
| Nextseason: | 1957–58 |
| Season: | 1956–57 |
The 1956–57 League of Ireland was the 36th season of senior football in the Republic of Ireland.
St Patrick's Athletic were the defending champions.
No new teams were elected to the League.
| Team | Location | Stadium | |
|---|---|---|---|
| Bohemians | Dublin (Phibsborough) | Dalymount Park | |
| Cork Athletic | Cork (Mardyke) | Mardyke | |
| Drumcondra | Dublin (Drumcondra) | Tolka Park | |
| Dundalk | Dundalk | Oriel Park | |
| Evergreen United | Cork (Turners Cross) | Turners Cross | |
| Limerick | Limerick | Markets Field | |
| Shamrock Rovers | Dublin (Milltown) | Glenmalure Park | |
| Shelbourne | Dublin (Ringsend) | Shelbourne Park | |
| Sligo Rovers | Sligo | The Showgrounds | |
| St Patrick's Athletic | Dublin (Phibsborough) | Dalymount Park | |
| Transport | Dublin (Harold's Cross) | Harold's Cross Stadium | |
| Waterford | Waterford | Kilcohan Park |
Shamrock Rovers won their eighth title and qualified for the following season's European Cup.
| Rank | Player | Club | Goals |
|---|---|---|---|
| 1 | Tommy Hamilton | Shamrock Rovers | 15 |
| Donal Leahy | Evergreen United | 15 | |
| 3 | Austin Noonan | 13 | |
| 4 | Jack Fitzgerald | Waterford | 12 |
| Dessie Glynn | Shelbourne | ||
| 6 | Willie Coleman | Drumcondra | 11 |
| Tommy Collins | Cork Athletic | ||
| Vincent Morrison | Sligo Rovers | ||
| 9 | Jackie McCourt | Drumcondra | 10 |
| Jack Walsh | Sligo Rovers | ||