"Cardigan" is a song by the American singer-songwriter Taylor Swift and the lead single from her eighth studio album, Folklore (2020).

The video has been described as following a cottagecore aesthetic, featuring Swift in three different settings: a "cozy cabin" in the woods, a moss-covered forest, and a dark stormy sea, which represents the concept of the different phases in relationships.

She conceived the record as figments of mythopoeic visuals in her mind, as a result of her imagination "running wild" while isolating herself during lockdown.

[22] Swift told her fans that "Cardigan" is about "a lost romance and why young love is often fixed so permanently within our memories".

[25] While promoting the limited edition version of the single, Swift told fans that she sent the original songwriting voice memo to Aaron Dessner on April 27, 2020, after hearing the instrumental tracks he created.

Callie Ahlgrim of Insider Inc. dubbed the lyrics of "Cardigan" as an "effective way to evoke young love and innocence lost", describing them as simple, sharp and extremely poignant.

[28] Pitchfork's Jillian Mapes wrote that the song's "overlapping details and central framing device—of a cardigan forgotten and found without a second thought—are pure Swift".

[31] The NME writer Hannah Mylrea defined the song as a "swirling amalgam" of gleaming production, swooning strings, flickering piano, and lyrics that exude pain from young love, and praised Swift's songwriting for "stunningly" conveying complex mixed emotions of hurt, jealousy and heartbreak in a "gorgeous" folk tune.

[32] Caragh Medlicott of Wales Arts Review deemed the song as "a resurgence of self-worth discovered, somewhat ironically, through the love of another".

[33] Uproxx's Philip Cosores stated that "Cardigan" is "rooted in the vivid details and melodic warmth that characterizes much of [Swift's] music".

[34] Entertainment Weekly's Maura Johnston felt the song's lyrics are "confident" but "slightly embittered", which she thought "pay off at the album's end".

[22] Billboard, on their list of 100 Best Songs of 2020, placed "Cardigan" at number 11, calling it "a lead single unlike anything Swift had released before.

[9] The "homespun" and "dreamlike" video starts out with Swift sitting in a candlelit cottage in the woods, wearing a nightgown and playing a vintage upright piano.

This scene also features a photograph of Swift's grandfather, Dean, who fought in the Battle of Guadalcanal, and a painting that she created during the first week of COVID-19 isolation.

[59] When the soundboard emanates golden sparkles, she climbs into it and finds herself magically transported to a moss-covered forest, where she plays the song on a grand piano producing a waterfall.

[60] She had the whole storyline—the whole notion of going into the piano and coming out into the forest, the water, going back into the piano.The music video was inspired by the period and fantasy films that Swift watched in isolation during the COVID-19 lockdown.

[62] As Swift had to remain unmasked for large amounts of time while filming, crew members wore color-coded wristbands to denote those allowed to come within close contact with her.

[67] Irish Independent described the cardigan as a bulky, "Clancy Brothers-style" Aran sweater, and added that Swift "at this rate, [will] be playing a bodhrán and belting out 'The Auld Triangle' on Hill 16".

[68] Irish national broadcaster Raidió Teilifís Éireann thanked Swift for putting cardigans "back on the map once more", following James Thomas Brudenell, Coco Chanel, Kurt Cobain and Elizabeth II.

[89] She performed a shortened version of "Cardigan" at the 63rd Annual Grammy Awards, as part of a medley with "August" and "Willow" (2020), in a cottagecore setting featuring a moss-covered cabin inside a forest, accompanied by the collaborators Dessner and Jack Antonoff.

[92] The Washington Post listed Swift's performance as the sixth best of the show, highlighting its Folklore-inspired special effects, such as "woodsy, mystical aesthetic" and "haunted-looking trees and glittering gold lights".

[93] The Billboard critic Heran Mamo called it a "Lord of the Rings-meets-Twilight fantasy", and ranked it the fourth best performance of the evening.

[97] In October 2020, the English singer-songwriter Yungblud covered "Cardigan" as part of his segment for BBC Radio 1's annual Live Lounge month.

He mashed-up the song with Avril Lavigne's "I'm with You" (2002), accompanying himself on an acoustic guitar, joined by a cellist and two violinists, resulting in a cheerful, strings-laden performance.