Calchas was a very famous seer widely featured in material about the Trojan War.
That said, there does seem to be special emphasis on women as seers, in that the Moirai, Parcae and the Norns, for example, are female. (This may have to do with weaving, which in many Ancient cultures, was strongly associated with women.)
The Pythonesses of Delphi certainly reinforce the association.
C.M. Weimar provided an excellent note about Tiresias, whom I had overlooked. What is especially salient is that Tiresias is an hermaphrodite. He was transformed into a woman when he hit a pair of copulating snakes with his stick. (A Freudian interpretation of what is going on there would not be out of bounds;) Tiresias was subsequently returned to manhood by leaving another pair of mating snakes unmolested, or alternately, trampling them to death.
Also interesting to note that Πυθώ (Pūthṓ) is phonetically similar to πίθος (píthos), which is associated with Pandora, the mother of the race of women," and that the words share some similar meanings. The root of putho can also refer to "depths, hollow" which is a characteristic of jars (pithoi), and further, can be said to represent a female sexual characteristic, similar to the "sheathe" origin of "vagina". Another meaning of putho definition as "rot or decay", which could be related to the noxious gasses that rise from the vents at Delphi, and also relate to the pithos of Pandora, which was associated with a decline of civilization per the evils borne in that jar.