The song was written by the two artists alongside Nate Mercereau, Steven Cheung, Theron Thomas, Torae Carr, and its producer Ricky Reed.

In October 2020, American singer and rapper Lizzo announced that her fourth studio album was nearing completion, saying she had "a few more songs to write".

[8] "Rumors" was written by Lizzo, Cardi B, Torae Carr, Theron Thomas, Nate Mercereau, Steven Cheung, and its producer Ricky Reed.

"[12] Rating it with five stars out of five, Nick Levine of NME stated that "Rumors" is a "brilliant return from Lizzo that combines her signature sense of fun with some well-placed spikiness.

"[13] Comparing it to "Truth Hurts", Eric Torres of Pitchfork wrote that the single "feels slapped together from different parts of Lizzo's past hits: the bellowing horns, squealing guitar solos, and endless confidence are all here.

[20][21] The video for "Rumors", directed by Tanu Muino, references the Muses from Disney's Hercules in a set inspired by ancient Greece.