1978 Rio de la Plata Championships

The 1978 Rio de la Plata Championships, also known as the River Plate Championships, was a women's singles tennis tournament played on outdoor clay courts in Buenos Aires in Argentina. The event was part of the A category of the 1978 Colgate Series. The tournament was held from 30 October through 5 November 1978. Third-seeded Caroline Stoll won the singles title and earned $6,000 first-prize money.

Singles
🇺🇸 Caroline Stoll defeated 🇦🇷 Emilse Raponi 6–3, 6–2
 * It was Stoll's 1st title of the year and the 1st of her career.

Doubles
🇫🇷 Françoise Dürr / 🇺🇸 Valerie Ziegenfuss defeated 🇺🇸 Laura DuPont / Regina Maršíková 1–6, 6–4, 6–3