I've organized the names here into a few broad categories just to keep this from being a huge impenetrable wall of text, but there's a ton of stylistic variation within each category, and overlap between them. For painters who mix figuration and abstraction, I just picked the category I thought was the closer fit. All of these are artists I personally like, so they're mostly contemporary, and this is (obviously) nowhere close to being an exhaustive list of significant female artists in any style or medium. I'll add more names as I think of them or find them. Living/currently working artists are in blue :)
Abstractionists: Miyoko Ito, Hilma af Klint, Agnes Martin, Joan Mitchell, Helen Frankenthaler, Cecily Brown, Judy Chicago, Agnes Pelton, Aigana Gali, Elaine de Kooning, Grace Hartigan, Donna Huanca, Francesca Mollett, Anne Appleby, Amy Sillman, Bernice Bing, Louise Fishman, Michael (Corinne) West, Olga Albizu, Loie Hollowell, Lee Krasner, Wook-kyung Choi
Figurative painters: Georgia O'Keeffe, Marlene Dumas, Jane Freilicher, Jennifer Packer, Mary Newcomb, Tamara de Lempicka, Mamma Andersson, Agnes Treherne, Mary Fedden, Nicole Eisenman, Dana Schutz (controversial, but make your own judgments), Florine Stettheimer, Sue Bright Lautmann Hertel, Shara Hughes, Joani Tremblay, Lois Dodd, Rosa Loy, Marion Wagschal, Amrita Sher-Gil, Susan Rothenberg, Tatiana Blass, Suzanne Valadon, Michiko Itatani, Zinaida Serebriakova
Surrealists: Leonora Carrington, Remedios Varo, Leonor Fini, Toyen, Gertrude Abercrombie, Jane Graverol, Marion Adnams, Rachel Baes, Emmy Bridgwater, Kay Sage, Dorothea Tanning, Bridget Bate Tichenor, Maria Anto
Textiles, Sculpture, Printmaking, Conceptual Art
Textile artists: Tracey Emin (she's worked in a lot of mediums, but I'm mainly a fan of her quilts), Faith Ringgold (insane quilter), Gunta Stölzl (legendary Bauhaus weaver), Anni Albers (another Bauhaus legend), Otti Berger (another), Olga Fisch (another), Olga de Amaral, the Gee's Bend quilters, Mary Walker Philips, Woomin Kim, Sheila Hicks, Maris Van Vlack (one of the best textile artists currently working, and she's still a student!), Erin M. Riley, Samantha Bittman, Mrinalini Mukherjee
Sculptors, printmakers, conceptual artists: Ana Mendieta, Louise Bourgeois, Roni Horn, Kiki Smith, Ruth Asawa, Käthe Kollwitz, Germaine Richier, Erika Verzutti, Elaine Cameron-Weir, Eva Hesse, Senga Nengudi, Leonor Antunes, Alicja Kwade, Edith Dekyndt, Alice Channer, Lubna Chowdhary