Sunny is based on the 2018 novel The Dark Manual by Irish writer Colin O'Sullivan, and was created for television by Katie Robbins.

The series was filmed on location in Japan, with production announced in February 2022 and filming beginning in July of that year.

Rashida Jones starred in the lead role and also served as an executive producer on the series.

Hidetoshi Nishijima joined the cast in July 2022 as filming began, while Joanna Sotomura, annie the clumsy, You, Judy Ongg, and Jun Kunimura were added to the cast in October 2022.

The robot character Sunny is voiced by Joanna Sotomura rather than played by a human actor on screen.

Apple TV+ cancelled Sunny after just one season, in November 2024.

The series received generally positive reviews, holding a 90% approval rating on Rotten Tomatoes and a score of 68/100 on Metacritic.