XO was well received by critics upon its release. Mark Richardson of
Pitchfork wrote, "Smith's songwriting continues to improve, as each of [the album's] fourteen tracks displays his inarguable mastery of the pop song structure more clearly than ever."
Robert Christgau of
The Village Voice gave the album a one-star honorable mention rating, indicating "a worthy effort consumers attuned to its overriding aesthetic or individual vision may well like". His review described the album's music as "high tune, low affect," citing "Waltz #2 (XO)" and "Everybody Cares, Everybody Understands" as highlights.
XO placed at number five on
The Village Voice's 1998 end-of-year
Pazz & Jop poll. In its retrospective review,
BBC Music wrote, "the budget might have gone up, but Smith's masterful way with an understated melody and melancholic lyric remained firmly intact", calling
XO "perhaps the greatest long-player Smith released; if not, it's certainly the equal of the preceding
Either/Or. Repeat listens don't dull it in the slightest, every barbed one-liner and exhalation of despair perfectly preserved".
Trouser Press called the record "a tastefully commercialized production (completely with horns and strings) that respects Smith's privacy and, in fact, does him a solid service. [...] If the songs are not the most profound or developed of Smith's catalogue, it's still a great record that proves how durable integrity can be." A 2023 review by
Pitchforks Jayson Greene described the album as "a transformational landmark and a logical next step for the restless composer" and remarked that the "breadth and depth of
XO astonished even his benefactors". == Legacy ==