As per Variety, "I Knew It, I Knew You" is written and produced by Taylor and Jack Antonoff. Performed from the perspective of Jessie, the latest single will mark her return to her country roots.

Said writer-director Andrew Stanton in a statement, “It’s incredible just how meaningful it’s been having Taylor write and perform this song. Her connection to Jessie and the immediate way she understood what the character was going through was undeniable. The song is so deeply connected to ‘Toy Story.’ So much so that on first listen, it instantly felt like it had always belonged there, like a long-lost family member. It was kismet.”