The Sailor Starlights (Japanese: セーラースターライツ, Hepburn: Sērā Sutāraitsu) are a group of fictional characters in the Sailor Moon manga series created by Naoko Takeuchi. They are introduced in the fifth and last arc of the series, called Stars in the manga, Sailor Moon Sailor Stars in the original anime adaptation, and Sailor Moon Cosmos in the second anime adaptation. The Starlights debut in chapter #43 "Stars 1", originally published in Japan's Nakayoshi magazine on March 28, 1996.

The group itself is composed of Sailor Star Fighter, Sailor Star Maker, and Sailor Star Healer; when in civilian form they go by the pseudonyms Kou Seiya, Kou Taiki, and Kou Yaten respectively. They are from the fictional planet Kinmoku, which has been destroyed, and disguise themselves as male idols, The Three Lights (スリーライツ, Surī Raitsu), in order to hide their true identities as they search for their lost princess, Kakyuu.

The Starlights come from Kinmoku, a planet from another star system whose ruler, Princess Kakyuu, left to escape Sailor Galaxia's assault and heal her wounds. They tracked Kakyuu to Earth and then Japan, where they disguised themselves as the male pop star group The Three Lights and embedded their music with a telepathic broadcast to attract her attention. They attend Jūban High School along with Usagi Tsukino and her friends. Eventually, they manage to reunite with Kakyuu; however, while headed to the Galaxy Cauldron, Galaxia's henchwomen Sailor Chi and Sailor Phi kill them.

In the original anime adaptation, the Starlights were given a major role. On Earth, they physically change into males in their civilian forms and become women again when transforming into Sailor Guardians, as opposed to their manga counterparts, who disguise themselves as men as civilians. As Starlights, they distance themselves from the other Sailor Guardians, deeming that Earth is not their responsibility. They survive several direct battles with Galaxia herself, and help Sailor Moon defeat Chaos to save Galaxia.

The Starlights are featured in several of the Sailor Moon musicals (Sailor Stars, Eien Densetsu, and their revised editions, as well as Ryuusei Densetsu, Kakyuu-Ouhi Kourin and Le Mouvement Final). Despite being portrayed by women, it is meant to be ambiguous as to whether they take on male forms or cross-dress, though their personalities reflect the former. Their story also combines elements from both the manga and the anime; for instance, they travel to the Galaxy Cauldron as in the manga, but survive the battles against Galaxia as in the anime. The pairings with the Sailor Guardians from the anime are also featured in some musicals.

Kou Seiya (星野 光, Seiya Kō), also known as Sailor Star Fighter (セーラースターファイター, Sērā Sutā Faitā), is the lead vocalist of the Three Lights. In general, Seiya acts arrogant and tends to be, at least on the surface, confident in her own abilities.

Seiya becomes the star player of their local high-school American football team and the school's star athlete, upsetting Haruka Tenoh, who was the previous star athlete on the track and field team. Eventually, Seiya raises the suspicions of the Sailor Guardians as to her identity. In the anime, Taiki and Yaten consider her to be prone to bouts of childishness, such as when she shows off her basketball skills before the school, but generally follow her lead.

Seiya develops strong feelings for Usagi, calling her odango, like Mamoru does, with Seiya's attempts to forge a bond with her providing the primary romantic tension of the season. The two go on a date at an amusement park, which is interrupted when Sailor Iron Mouse attacks. Seiya makes her interest in Usagi clear when they spend time together practicing softball, telling her, "I like your light." However, her feelings are not reciprocated and she acknowledges the one-sided romance.