Passages from Claudia Gray's Leia: Princess of Alderaan novel imply that the Resistance's Vice Admiral Amilyn Holdo, played by Laura Dern in Star Wars: The Last Jedi, may be either bisexual or pansexual.
The hint that Holdo may not be straight comes during a conversation with Leia about the possibility of an interspecies relationship:
"A pair of pretty dark eyes." Then Amilyn thought about that for a moment. "Or more than a pair, if you're into Grans. Or Aqualish, or Talz. Or even – "
"That's all right! Leia said through laughter. "It's just humanoid males for me."
"Really? That feels so limiting."
"Thank goodness it's a big galaxy."
Although the passage doesn't explicitly state that Holdo is bisexual or pansexual, it notes she's interested in more than just humanoid men. While there are many alien species in the Star Wars universe that are both humanoid and non-humanoid, some don't fall into a strict gender binary. The insectoid Xi'Dec, for example, have more than 180 different sexes. Other species are hermaphroditic or have a third sex.
This also leaves open the possibility that, when dealing with a humanoid species that does use a gender binary, Holdo may be equally as interested in females as males.
Holdo will make an appearance in The Last Jedi, but there's no indication whether the film will make reference to her sexuality. If it does, she will become the first openly LGBT character depicted in a Star Wars film.
Star Wars has made strides in representation with its casting choices. However, explicitly LGBT characters are still lacking in the films. In 2016, J.J. Abrams, who directed The Force Awakens and is producing The Last Jedi, said it was time for the franchise to introduce gay characters. Several LGBT characters appear in the Extended Universe and, in particular, games such as Bioware's Star Wars: The Old Republic MMORPG.
Arriving Dec. 15, director Rian Johnson's Star Wars: The Last Jedi stars Mark Hamill as Luke Skywalker, Carrie Fisher as General Leia Organa, Adam Driver as Kylo Ren, Daisy Ridley as Rey, John Boyega as Finn, Oscar Isaac as Poe Dameron, Lupita Nyong'o as Maz Kanata, Domhnall Gleeson as General Armitage Hux, Anthony Daniels as C-3PO, Gwendoline Christie as Captain Phasma and Andy Serkis as Supreme Leader Snoke.
(via Screen Rant)