Earlier this year, the Seventh Circuit held under “[t]he logic of the Supreme Court’s decisions, as well as the common-sense reality that it is actually impossible to discriminate on the basis of sexual orientation without discriminating on the basis of sex,” Title VII prohibits discrimination based on sexual orientation. Hively v. Ivy Tech Cmty. Coll., 853 F.3d 339, 350-51 (7th Cir. 2017) (en banc).
The Second Circuit is currently considering the same issue en banc in Zarda v. Altitude Express.
But the case that may eventually end up before the Supreme Court is Evans v. Georgia Regional Hospital out of the Eleventh Circuit. SCOTUSblog has the petition for cert here (link). The Eleventh Circuit held that petitioner could not “state a claim under Title VII by alleging that she endured workplace discrimination because of her sexual orientation.” Pet. App. 11a. The majority noted that circuit precedent from 1979 dictated that “[d]ischarge for homosexuality is not prohibited by Title VII.” Id. 11a (quoting Blum v. Gulf Oil Corp., 597 F.2d 936, 938 (5th Cir. 1979)).
Given the circuit split, it would seem likely that the Supreme Court consider this case.