Yes, Jane Eyre is a feminist novel. From its first reception, when Jane's passionate nature was criticized, up until today, people have understood Jane as a heroine fighting for her freedom within a social system that oppressed women.
As a governess, Jane has ideas that sound as if they come from an early feminist manifesto. Victorian readers condemned the passionate thoughts Jane expressed as unfeminine:
Women are supposed to be very calm generally: but women feel just as men feel; they need exercise for their faculties, and a field for their efforts, as much as their brothers do; they suffer from too rigid a restraint, too absolute a stagnation, precisely as men would suffer; and it is narrow-minded in their more privileged fellow-creatures to say that they ought to confine themselves to making puddings and knitting stockings, to playing on the piano and embroidering bags. It is thoughtless to condemn them, or laugh at them, if they seek to do more or learn more than custom has pronounced necessary for their sex.
In the late 1970s, English professors Gilbert and Gubar wrote a famous book called Madwoman in the Attic arguing that Eyre should be pronounced "ire," meaning anger, and noting that the angelic Helen had the last name "burns," also representing the anger women felt at being forced into an unnatural docility. The novel, they argued, is about women's anger at their repression.
Beyond her anger, Jane reveals herself to be a strong woman who thinks and acts for herself, determining her own fate. As a child, she shows her strength when she rebels against the abuse she suffers at the hands of a bullying male cousin. As an adult, she refuses to marry Rochester after she finds out he has a wife, for as much as she loves him, such an act would violate her conscience. She would rather run away and take her chances alone than live in a demeaning relationship. Later, she refuses marriage to St. John because she does not love him and does not want her needs subordinated to his desire to be a missionary.
Jane's courage in making her decisions, in being self-supporting as a governess, in desiring more than the narrow life expected of a woman, in living with integrity and in refusing to sacrifice herself to men adds up to a feminist heroine at the heart of a novel that calls into question how women are treated by the larger society.