"Unholy" is a song by English singer Sam Smith and German singer Kim Petras. It was released on 22 September 2022 through EMI Records and Capitol Records as the second single from Smith's fourth studio album Gloria (2023) and as a bonus track on Petras's debut studio album Feed the Beast (2023). It was teased by Smith on their TikTok account a month before its release and went viral due to its use in thirst trap-style videos. Produced by Ilya, Omer Fedi, Blake Slatkin, Jimmy Napes, and Cirkut and written by them alongside Smith and Petras, "Unholy" is a sexually charged electropop, dance-pop, and synth-pop song with choral and hyperpop influences, which marked a shift away from ballads for Smith. It uses the Phrygian dominant scale and its lyrics are about a family man who cheats on his wife at a strip club. "Unholy" received mostly positive reception from critics, many of whom considered the song a standout from Gloria and praised its sound as catchy yet unusual, while others found the song less transgressive than it was intended to be and criticized Petras's verse. Its win for Best Pop Duo/Group Performance at the 65th Annual Grammy Awards made Petras the first openly transgender artist to win a major-category Grammy Award. "Unholy" topped the UK Singles Chart for four weeks and the Billboard Hot 100 for one week, making Smith and Petras the first openly non-binary and openly transgender solo artists, respectively, to have a number-one song on the latter chart. It also topped the charts in 18 other countries and the Billboard Global 200 chart. The music video for "Unholy", directed by Italian-Canadian director Floria Sigismondi, depicts Smith and Petras performing at an erotic cabaret with burlesque dancers to a woman who follows her adulterous husband there. It features cameos from American drag queens Violet Chachki and Gottmik and gay pornographic actor Paddy O'Brian. "Unholy" was performed live by Smith on their 2023 headlining concert tour, Gloria the Tour, on an episode of Saturday Night Live, at the 65th Annual Grammy Awards–where Smith and Petras's Satan-themed performance caused controversy among American conservatives, who accused the artists of devil worship–and at the Brit Awards 2023.