Agatha All Along is an American television miniseries created by Jac Schaeffer for the streaming service Disney+, based on Marvel Comics featuring the character Agatha Harkness. A spin-off from the series WandaVision (2021), it is the 11th television series in the Marvel Cinematic Universe (MCU) produced by Marvel Studios and the first to be released under its Marvel Television label, sharing continuity with the films of the franchise. Schaeffer serves as showrunner and lead director.

Kathryn Hahn reprises her role as Agatha Harkness from WandaVision, with Joe Locke, Debra Jo Rupp, Aubrey Plaza, Sasheer Zamata, Ali Ahn, Okwui Okpokwasili, Patti LuPone, Evan Peters, Maria Dizzia, Paul Adelstein, and Miles Gutierrez-Riley also starring. Development began in October 2021, with Schaeffer and Hahn attached, and the series was formally announced the next month. Schaeffer, Rachel Goldberg, and Gandja Monteiro were set as directors in early 2023 ahead of filming, which took place from January to May 2023 at Trilith Studios in Atlanta, Georgia, and in Los Angeles. Cast and crew returned from WandaVision, including the series' musical team. Several different titles were announced for the series as part of a marketing campaign before the official title of Agatha All Along—referencing the song of the same name from WandaVision—was announced in May 2024.

Agatha All Along premiered on Disney+ on September 18, 2024, and ran for nine episodes until October 30. The series is part of Phase Five of the MCU. It received positive reviews from critics, with praise for its production value, humor, and the cast's performances, especially those of Hahn, Locke, LuPone, and Plaza.