Galaxy Theatre, Theatre in Higashi-Shinagawa, Japan

The Galaxy Theatre is a performance venue in Higashi-Shinagawa, Tokyo, offering seating for 746 visitors spread across three levels. The horseshoe-shaped arrangement of rows allows the audience to view the stage from multiple angles, while special boxes on the second and third levels provide additional seating options.

The venue opened in 1992 inside the Sea Fort Square complex under the name Art Sphere. In April 2006 the operator changed to a Horipro group company, and it reopened that October as Tennozu Galaxy Theatre. In February 2016 Yoyogi Animation Gakuin and its parent Kyoden Area Net acquired the facility; a planned 2017 renaming to Tennozu YOANI Theatre was dropped after agreement with Horipro, which held the trademark. In December 2025 Nelke Planning took over operations through its subsidiary Galaxy Theatre.

The venue opened in 1992 as Art Sphere and took its current name in October 2006, when the operator became a Horipro group company. A plan to rename it Tennozu YOANI Theatre in April 2017 was dropped after agreement with Horipro, which held the trademark, so the Galaxy Theatre name stayed. A cafe-bar, STRA DE ROUGE, operated inside until it closed on 1 April 2018.

The theatre sits inside Sea Fort Square in Tennozu Isle. From Tennozu Isle Station on the Tokyo Monorail Haneda Airport Line it is about a one-minute walk; from exit A of the Rinkai Line station it is about five minutes. The hall is a three-tier horseshoe with boxes on the second and third floors.

The hall is a horseshoe-shaped, three-storey open space, and the farthest seat is no more than 20 metres from the stage. Box seats are set on the second and third floors. The venue opened in 1992 as Art Sphere and was renamed Galaxy Theatre in October 2006 after a renewal.