1899 River Plate Rugby Union Championship
| 1899 RPRU | |
|---|---|
Lomas A.C., the first Argentine champion | |
| Countries | ARG |
| Number of teams | 5 |
| Champions | Lomas |
| Runners-up | Rosario A.C. |
| Relegated | (None) |
The 1899 River Plate Rugby Union Championship was the inaugural season of the first rugby union club championship held in Argentina, organised by the "River Plate Rugby Union" (current Argentine Rugby Union). It was contested by the five founding members of the RPRU: Belgrano, Rosario, Lomas, Buenos Aires, and Flores.
Uruguayan club Montevideo C.C. was invited to take part of the competition but they declined to participate due to the long travel time to Argentina by ship.
In the inaugural game, Lomas defeated Buenos Aires by 11-4. Lomas would be the first Argentine champion, winning the title at the end of the season.