The project was first teased during an Instagram Live broadcast by Justin Vernon, where he revealed a snippet of the song "We" and showed a list of working titles. After the band's performance at All Points East 2019, they premiered two new songs, "U (Man Like)" and "Hey, Ma," which were released as singles the following day, along with dates for their fall 2019 tour. On July 11, they announced that their fourth album, i,i, would be released on August 30 (later moved to August 9) and shared the singles "Jelmore" and "Faith." The band likened the album to fall, completing a cycle that began with the "winter" of For Emma, Forever Ago (2007), followed by the "spring" of Bon Iver, Bon Iver (2011), and the "summer" of 22, A Million (2016). Vernon described the album as "the most adult record" and "more honest, generous work." It was recorded over an extended period at April Base in Wisconsin and completed at Sonic Ranch in Texas. On July 31, 2019, the band released a documentary short called Bon Iver: Autumn, featuring Vernon and bandmates discussing the new album and the upcoming tour. To promote the album, listening parties were held on August 7 in several countries.

On August 8, without prior announcement, eight of the album's nine remaining songs were released digitally (one each hour), with the ninth, "Yi," posted on Reddit. The band then moved the album's digital release date to August 9, with the physical release on August 30.