1978 South American Championships
Date	20–26 November
Edition	12th
Category	Grand Prix Super Series
Draw	32S / 16D
Prize money	$175,000
Surface	Clay / outdoor
Location	Buenos Aires, Argentina
Champions
Singles
José Luis Clerc[1]
Doubles
Chris Lewis / Van Winitsky[2]
← 1977 · South American Championships · 1979 →

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 Víctor Pecci 6–4, 6–4

• It was Clerc's 2nd singles title of the year and 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.