With The Hudson Dusters, along with a second Joni Mitchell song: Clouds. See: Clouds (Both Sides Now).
Fairport Convention [go-betweened by their producer Joe Boyd, who booked Joni's first UK tour late '67; Fairport first cut a version for the BBC]
Jennifer [young Jennifer Warnes]
Gloria Loring [also pre Joni]
Joni Mitchell [author; her oldest own version on tape ('67) came out on Joni Mitchell Archives Vol 1 in 2020]
Judy Collins [this version inspired Bill & Hillary Clinton to name their daughter Chelsea]
Part of Joni Mitchell's second album Clouds and also selected for the Hits part of her Hits & Misses compilations, although the song never charted. Unless she counts the amount of covers for hit value. Chelsea Morning matches the standard. It's the New York Chelsea we're talking about, Joni being an ex resident of the Chelsea Hotel. Soho and Chelsea being both well represented in New York and in London, made it easier for a British band as Fairport Convention to go for it, even before the author.