Smiling Friends is an adult animated television series created by Zach Hadel and Michael Cusack for Cartoon Network's nighttime programming block Adult Swim, which revolves around the surreal misadventures of a small charity and its four employees dedicated to spreading happiness. The show utilizes a wide variety of different art styles and animation techniques, which include but are not limited to stylized traditional animation, computer animation, rotoscoping, stop motion, flash animation, and live-action.

The pilot episode aired April 1, 2020, unannounced as part of Adult Swim's annual April Fools' Day event alongside the premiere of Cusack's other series, YOLO. On May 19, 2021, Adult Swim ordered a full season that was initially set to premiere in late 2021. A panel dedicated to the series was held during the Adult Swim Festival on November 12, 2021, where co-creator Zach Hadel mentioned the show would premiere "within a few months", pushing the release schedule ahead to 2022. The first season contains nine episodes, including the pilot and an 11-minute special. The first season eventually premiered on January 10, 2022, with Adult Swim airing all episodes of the season, except for the special, in one night despite initial plans for a weekly release.

The series received critical acclaim and a cult following, and was renewed for a second season on February 9, 2022. The season premiere aired on April 1, 2024, with the rest of the season beginning to air on May 13. On June 13, 2024, Adult Swim renewed the series for a third season. The third season was previewed at Annecy on June 11, 2025. On the same day, it was announced the show was renewed for a fourth and fifth season.