1978 South American Championships (tennis)
| 1978 South American Championships | |
|---|---|
| Date | 20–26 November |
| Edition | 12th |
| Category | Grand Prix Super Series |
| Prize money | $175,000 |
| Surface | Clay / outdoor |
| Location | Buenos Aires, Argentina |
| Champions | |
| Singles | |
 José Luis Clerc | |
| Doubles | |
 Chris Lewis /  Van Winitsky | |
The 1978 South American Championships was a men's Grand Prix tennis circuit tournament held in Buenos Aires, Argentina and played on outdoor clay courts. The event was held from 20 November through 26 November 1978. Fourth-seeded José Luis Clerc won the singles title.
Finals
Singles
José Luis Clerc defeated 
Victor Pecci 6–4, 6–4
- It was Clerc's 2nd title of the year and the 2nd of his career.
Doubles
Chris Lewis / Van Winitsky defeated José Luis Clerc / 
Belus Prajoux 6–4, 3–6, 6–0
- It was Lewis' 3rd title of the year and the 5th of his career. It was Winitsky's 2nd title of the year and the 2nd of his career.