2012: International promotions, sub-unit formation, and Japanese return

On January 12, 2012, the group attended the Golden Disk Awards, held in Osaka, bringing home two awards: the "Digital Bonsang" and the highly coveted "Digital Daesang". A week later, on January 19, 2012, they attended the Seoul Music Awards, and brought back two awards, the "Bonsang" and "Popularity" awards. The group also won two awards from the Gaon Chart Awards, winning the Album Of The Year for the fourth Quarter and Oricon "Hallyu Singer" award. On February 24, 2012, the teaser for their Japanese digital single, "Time Machine", was released. The song was originally included in the Japanese repackaged version of their first Japanese album. The full music video was released on March 13, 2012, with the song peaking fourteenth on Billboard Japan's Hot 100.

Girls' Generation perform "The Boys" at theSeoul Music Awards, January 19, 2012.

Their appearances on the Late Show with David Letterman and Live! with Kelly on January 31, 2012, and February 1, 2012, where they performed remixes of the English version of "The Boys", marked the first time that a Korean musical act has performed on each of the shows. They also performed on the French show, Le Grand Journal, on February 9, 2012, after it was announced that they were to release "The Boys" on February 13, 2012, through Universal Music Group’s Polydor Records in France. In the same month, Forbes Korea reported the year's list of the "Top 40 Power Celebrities". Girls' Generation ranked number one on the list, thus making them the most powerful South Korean girl group and female celebrity.A month later, on 23 March 2012, they made their debut performance in Malaysia at the Petronas Towers, as part of "Twin Towers @Live 2012.Figures for the groups total earnings for 2011 were released in March, 2012. The group placed first among their label, earning over 100 billion won, or, approximately, $88.56 million USD.

April 2012 saw the formation of Girls' Generation-TTS, or simply "TaeTiSeo", a subunit composed of members Taeyeon, Tiffany, and Seohyun. The subgroup released their first mini-album, Twinkle, on May 2. The group continued promotion throughout the month, performing on variety shows and at the Hallyu Dream Wave Concert. "Twinkle" debuted at number 126 on the Billboard 200, selling over 3,000 copies and making it the highest charting K-Pop album on the chart. By July, 2012, the album had sold 140,000 copies in its native country, and a further 24,000 copies abroad.

That same month, the group, with the exception of Yuri and Yoona, attended the showcase for S.M. Entertainment's biographical movie,I AM., which was held at the CJ CGV cinema in Yeongdeungpo-gu, Seoul, on April 30.A week prior, "Dear My Family", the theme song for the film, which featured group leader, Taeyeon, and fellow S.M artists, was released, featuring both concert and backstage footage.

On May 20, 2012, the group performed with their label-mates at the Honda Center in Anaheim, on the SMTown Live World Tour III. Members Yoona and Yuri were not present due to their filming commitments with their television dramas Love Rain and Fashion King, respectively. Following the conclusion of their dramas, Yuri and Yoona returned to the group as the tour moved on to Taiwan, where they performed to a crowd of 30,000 people. The tour will then continue into Tokyo, Seoul, Beijing, the U.S. and Europe.

A teaser video for the group's Japanese single, "Paparazzi", was released on May 29, 2012. This teaser was followed by the release of the full music video, in addition to a dance version, on June 14, 2012. The song, released on June 27, 2012, will serve as the lead single from their upcoming second Japanese-language album. Paparazzi proved to be another successful release for the group, debuting atop the Japanese Hot 100, selling over 92,000 copies in its first week, becoming their second best first week opening, following the 102,000 debut of Mr. Taxi, a year prior. "Paparazzi"'s release, boosted the groups total single sales in the country to over 647,000, according to SoundScan Japan. That same month, the group won "Best Album of the Year" for their debut Japanese album, at the 2012 VMAJs, beating out the likes of Lady Gaga and fellow K-Pop artist, KARA.It was announced on July 3, 2012, that the group was to release official stamps the following month, commemorating their 5th Anniversary. A total of 14 stamps were produced, which included autographed album covers. This marked the first time a celebrity had made a contract with Korea Post to produce stamps.Within an hour of the stamps' issuing, over half of the available stamp sheets had already sold out.

On August 10, 2012, it was revealed that the group was to release the second single from their upcoming second Japanese album. The still untitled single is set for release on September 26, the same day a Blu-ray/DVD videography titled Girls' Generation Complete Video Collection of the group is set for release. The group will also be representing South Korea at the first ABU TV Song Festival 2012, which is scheduled to take place at the KBS Concert Hall on October 14. They also performed at the '14th Korea-China Music Festival', which was held at the Yeosu Expo Digital Gallery.

On August 29, the group's official Japanese fansite announced the group's intention to tour Japan for the second time, in 2013