The 1978 Toray Sillook Open was a women's singles tennis tournament played on indoor carpet courts at Yoyogi National Gymnasium in Tokyo in Japan.

The event was part of the AAA[a] category of the 1978 Colgate Series.

It was the sixth edition of the tournament and was held from 14 September through 17 September 1978.

[2] First-seeded Virginia Wade won the title and earned $20,000 first-prize money.

[2][1] Virginia Wade defeated Betty Stöve 6–4, 7–6(7–2)