The 1973 Fred Perry Japan Open Tennis Championships was a combined men's and women's tennis tournament played on outdoor hard courts and took place in Tokyo, Japan.

The tournament was held from 8 October through 14 October 1973.

The men's events were part of the 1973 Commercial Union Assurance Grand Prix circuit and graded as B category whereas the women's competition was a non-tour event.

Ken Rosewall won the men's singles title, earning him the $12,000 first prize, while Evonne Goolagong won the women's singles event and received $5,000.

[3][4] Ken Rosewall defeated John Newcombe, 6–1, 6–4 Mal Anderson / Ken Rosewall defeated Colin Dibley / Allan Stone, 7–5, 7–5 Evonne Goolagong defeated Helga Niessen Masthoff, 6–3, 6–4