Since its release, Celeste has garnered a dedicated fandom and an active speedrunning community. On September 9, 2019, a free downloadable content (DLC) expansion named Farewell was released, introducing a new chapter to the game. The development team have stated that they do not intend to create a sequel for the main game, however a sequel to Celeste for PICO-8 titled Celeste 2: Lani's Trek was released in January 2021.
Madeline and Badeline appeared as crossover characters in the Nintendo Switch version of TowerFall, released on September 27, 2018. In October 2018, Scarlet Moon Records announced Prescriptions for Sleep: Celeste, an album of Celeste cover songs described by Nintendo Life as "lullaby-style renditions" of the game's soundtrack. Prescriptions for Sleep: Celeste features violin by Maiko, saxophone by Norihiko Hibino, and piano by AYAKI, with Raine serving as co-producer. An open pre-order window for a Celeste collector's edition produced by Limited Run Games began on January 1, 2019. On January 21, it was announced that the game's soundtrack would receive an album of piano covers by Trevor Alan Gomes, titled Celeste Piano Collections, a part of the Piano Collections series by Materia Collective, released on January 25. In July, Materia Collective purchased the publishing rights for the music, and the composers of the game's B-side music went without royalties for 17 months. For its fifth anniversary in January 2023, it was announced that a new Celeste collector's edition from Fangamer would release that June.
In December 2018, Thorson announced that additional downloadable content (DLC) levels for Celeste would be released in "early 2019". The final chapter of Celeste, Farewell, was released as free DLC on September 9, 2019, however the team noted that the Xbox One version would have a slight delay. 2b1af7f3a8