She got there by dominating sixth-seeded Ana Ivanovic 6-2, 6-4 in today's semifinals.
Williams tumbled down the world order after starting the year injured, and at number-31 is the lowest-ranked woman to reach the final since the rankings began in 1975.
Top seed Justine Henin and Marion Bartoli are playing for the right to meet Williams in tomorrow's finale. Henin needs an All England title to complete a career Grand Slam.
Top seed Roger Federer, number-two Rafael Nadal and fourth-seeded Novak Djokovic moved into the men's semifinals with victories earlier in the day.