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[a] category of the 1978 Colgate Series.

The tournament was held from 30 October through 5 November 1978.

[2] Third-seeded Caroline Stoll won the singles title and earned $6,000 first-prize money.

[2][1] Caroline Stoll defeated Emilse Raponi 6–3, 6–2 Françoise Dürr / Valerie Ziegenfuss defeated Laura DuPont / Regina Maršíková 1–6, 6–4, 6–3