Infobox
A border for the cover art is needed as well as alt text to describe it to visually impaired readers. See {{Infobox single and WP:ALT.
Multiple values in the format and writers sections should be separated using {{Flatlist}}. Multiple values in the producer section should be separated using {{Plainlist}}
No label or recording information?

Lead
"It was released in various countries" -> vague wording.
"The number has been certified" -> rather use "the song" or "One Thing".
Add when the music video was released and the reception it received.
"televised programs" -> should be 'programmes' and some examples of which programmes are beneficial to this section. 

Background
"all of which" -> redundant.
Examiner.com is a blacklisted source, unfortunately.
Up All Night is overlinked
"various European countries" -> vague wording.
Linking "digital", "b-side" and "CD single" would be beneficial.
"was confirmed by 25 January 2012" -> was confirmed on 25 January 2012
"was chosen as second US single" -> was released as the second US single.

Composition and critical response
The two sections could be split with more detail? The song is notable enough to have more than only 7 reliable reviews?
A music sample maybe?
"One Thing" is an upbeat, uptempo, pop rock number which is... -> "One Thing" is an uptempo pop rock song with a length of three minutes and ten seconds. 
The comparisons to "What Makes You Beautiful" and "I Want It That Way" could be used as the last sentence of the Composition section as follows -> Musically, "One Thing" has been likened to "What Makes You Beautiful" and the Backstreet Boys' "I Want It That Way" (1999).
"The" is used too much as an introduction to sentences.
"alongside the bridge, is backed by wordless chants" -> alongside the bridge, and is backed by wordless chants.
"Its instrumentation includes" -> This sentence will fit better as the second sentence of this section.
"Due to" is a word to avoid.
"number" -> song/track
"Brian Mansfield from USA Today thought the song's..." -> felt that the song's
"Lewis Corner from Digital Spy gave the song four out of five stars, complimented" -> replace "gave" with "awarded" and the sentence is very deconstructive and redundant, rather quote a sentence or two from the review.
"while Entertainment Weekly writer" -> avoid the word "while" as much as possible.

Commercial performance
"from the parent album" -> from its parent album.
"When "One Thing" and "What Makes You Beautiful" ..." -> One Direction became the second act of 2012 to have two singles simultaneously occupying the chart's top ten when "One Thing" was at number six and "What Makes You Beautiful" at number ten for the chart week ending 22 April 2012.

Music video
This section is extremely brief. More info to what happens in the video, its synopsis and reception?
A snapshot from the video maybe?

Live performance
Some more details or reviews about the performances?
No Credits and personnel section?

Chart
South Korea (Gaon) would look better

References
Digital Spy, Hearst Corporation, Music Week is overlinked.
The iTunes refs could have the country abbreviations in brackets so that all the references do not look the same.
Ref 15, 21, 24, 25, 46, 52 are Uncategorised redirects, archive it maybe?
Ref 10 needs a  tag.

I'm putting the article on hold! Good luck! -) —  • these wings are made to fly!