Veteran Venus Williams defeated fellow American Alison Riske 6-1 7-6(2) to reach the final of the Stanford Classic in California on Saturday.
Williams will play for her 50th WTA title in Stanford in the tournament where she made her professional debut 22 years ago.
Konta, who is ranked 18th in the world, reached her first career WTA final with a 6-4 6-2 victory over second seed Slovakian Dominika Cibulkova.
The 36-year-old Williams, who won the Stanford title in 2000 and 2002, won her 49th career singles title in Taiwan in February.
Konta, who reached the semi-finals of the Australian Open in January, and at Eastbourne in June, has recovered impressively since a disappointing second-round exit at Wimbledon in June.