The Westfield Sydney to Melbourne Ultramarathon was an annual ultramarathon foot race held between 1983 and 1991. It was sponsored by the Westfield Group, with the start being at Westfield Parramatta shopping centre and the finish at Westfield Doncaster shopping centre (formerly known as "Doncaster Shoppingtown").The event was the brainchild of Martin "Alby" Noonan, a keen and talented distance runner who at the time was the Marketing and Promotions Manager for the Westfield Doncaster shopping centre.

The five-day event, which ranged in distance from 864 kilometres (537 miles) to 1,060 kilometres (660 miles), was regarded as one of the toughest in the world. It was particularly notable for having been won in 1983 by Cliff Young, an almost unknown 61-year-old potato farmer from Beech Forest, Victoria.

Yiannis Kouros won the men's race five times. In 1988, the race organiser challenged him to start 12 hours behind the rest of the field.^[1] Kouros overtook his competitors and won the race with a one-hour lead over New Zealander Dick Tout.^[2]

The first woman to compete was Australian Caroline Vaughan who ran in 1984.^[3] Vaughan did not finish the race. In 1985, three women competed and finished: British ultramarathon runner Eleanor Robinson (then Eleanor Adams), Donna Hudson of the US and Australian Margaret Smith. Robinson won the women's race three times.

The final running of the event included prize money ($60,000 for first place), a handicapping system and a change to the course. It ceased being held when the Westfield Group withdrew its support.