| Date: | 8–14 January |
| Edition: | 98th |
| Category: | World Series (men) Tier III (women) |
| Surface: | Hard / outdoor |
| Location: | Sydney, Australia |
| Champms: |  Yannick Noah |
| Champws: | Natasha Zvereva |
| Champmd: |  Pat Cash / Mark Kratzmann |
| Champwd: | Jana Novotná / Helena Suková |
| Before Name: | New South Wales Open |
| Main Name: | Sydney International NSW Open |
The 1990 Holden NSW Open (known as such in 1990 for sponsorship reasons[1]) was a combined men's and women's tennis tournament played on outdoor hard courts. It was the 98th edition (the 22nd edition in the Open Era) of the event known that year as the Holden New South Wales (NSW) Open, and was part of the ATP World Series of the 1990 ATP Tour, and the WTA Tier III tournaments of the 1990 WTA Tour. It took place at the White City Stadium in Sydney, Australia, from 8 to 14 January 1990. Yannick Noah and Natasha Zvereva won the singles titles.
See main article: 1990 Holden NSW Open – Men's singles. Yannick Noah defeated Carl-Uwe Steeb, 5–7, 6–3, 6–4
Natasha Zvereva defeated 
Barbara Paulus, 4–6, 6–1, 6–3
See main article: 1990 Holden NSW Open – Men's doubles. Pat Cash / Mark Kratzmann defeated Pieter Aldrich / Danie Visser, 6–4, 7–5
Jana Novotná / Helena Suková defeated Larisa Savchenko / Natasha Zvereva, 6–3, 7–5