Oh! is the second studio album by South Korean girl group Girls' Generation, released by SM Entertainment on January 28, 2010.^[2][3] It features the single "Oh!". A repackaged version, Run Devil Run was released on March 17, 2010, with the song "Run Devil Run" serving as the follow-up single.^[4]

Both Oh! and Run Devil Run were commercially successful in South Korea; Oh! ranked as the second best-selling album of 2010 on the Gaon Album Chart, with sales of 197,934 copies. Run Devil Run additionally ranked as the fourth best-selling album of the year, with 136,851 copies sold.^[5] At the 25th Golden Disc Awards, Girls' Generation became the first female group to win the Album Daesang prize in the ceremony's history with Oh!.

Initial interest for Oh! was high, as physical and online pre-orders of the album totaled 150,000 copies.^[6] Upon the album's full release, various album tracks charted in the top ten of various charts.^[7] In April 2010, one of the songs in their album entitled, "Forever" was featured on the OST of the drama Pasta.^[8] On its first day of sale, Oh! sold 30,000 copies.^[9] The album was released internationally via iTunes on February 8, 2010.^[10][11] The group began promoting their album on MBC's Show! Music Core on January 30.^[2][3] The group also performed "Show! Show! Show!" as a part of their special comeback performance on Show! Music Core and Inkigayo.

A repackaged version of the album, titled Run Devil Run, contained a new concept based around a "Dark Girls' Generation" theme. The new single "Run Devil Run" was released as a digital single on March 17, 2010.^[12] The demo version of the song was originally recorded by Kesha; however, the song's rights were then sold to SM Entertainment and subsequently given to Girls' Generation.^[4] The music video was released on March 18, with the group's first comeback performance taking place on Music Bank.^[4][13]

Kenzie, a songwriter who previously composed the group's debut single "Into the New World", also composed "Oh!".^[14] "Oh!" was released to digital music sites on January 25, 2010, and quickly topped various digital music charts within 10 minutes of release.^[15] It reached number one on the Gaon Digital Chart.^[16]

"Run Devil Run" was written by American songwriters, Alex James and Busbee, with Swedish songwriter Kalle Engström. The song was first recorded by American singer-songwriter Kesha in 2008 while pre-production of her debut album, Animal (2010) was underway; however, Kesha never included the song on the album. The song remained untouched for the next two years until executives at Universal Music Group sold the rights of the song to SM Entertainment. After this, Korean songwriter Hong Ji-yoo was brought on to translate and rearrange the English version of the song into Korean.

"Run Devil Run" received its first music show award on Music Bank, where it won over Kara's "Lupin" and 2AM's "I Was Wrong".^[17] It was ranked at number one on the Gaon Digital Chart for two weeks, making it their second number-one single on the chart.^[18][19] The B-side tracks also showed strong chart performance, with "Star Star Star" recording 1,480,417 digital downloads while "Show Show Show" recorded 1,020,710 digital downloads in 2010.^[20]

Han Dong-yoon of IZM felt that "Oh" was less interesting musically compared to "Gee" and "Genie".^[21] Han also gave Run Devil Run a negative review, where he questioned the group's abrupt change in concept by writing "The person who used to cutely cling to you and call you Yeon-buk oppa has now changed her attitude 180 degrees, saying she will now kick you to the curb".^[22] Seong Won-ho of the same publication gave the single "Run Devil Run" 1.5 stars out of 5, feeling that the translated Korean lyrics and vocals were a downgrade from the original version by Kesha.^[23]

"Oh!" was first performed live on January 30, 2010, on MBC's Music Core, as part of their "comeback stage".^[25] They also performed "Show! Show! Show!" However, there was a technical error in MBC's broadcast, with a few seconds of dead air near the end of the performance; the network was subsequently flooded with complaints.^[26] The incident was then parodied on YouTube, mixing in clips of the Korean drama IRIS, receiving attention from Korean netizens.^[27] The group followed up with their second performance on Inkigayo the following day.^[28]

Starting from March 11, 2010, photos of the members were released online showcasing a dark concept, so called Black SoShi.^[29] In the run of promotions for the song, an official iPhone application was released, available in free and paid versions. The free version has 30-second previews for all the songs on the album, a music video for “Run Devil Run” and a few photographs. The paid version has full tracks for all the songs on the album, music videos for "Run Devil Run", "Gee", "Oh!" and "Genie", and a photo gallery.^[30] They concluded their song promotions by the May 2, 2010, on Inkigayo. Beginning in 2011, the group embarked on their Girls' Generation Tour, which started on July 23, 2011, at the Olympic Gymnastics Arena in Seoul and ended at the Impact Arena in Bangkok on February 12, 2012.