Younha was born in South Korea on April 29, 1988, where she began to play the piano at the age of 5. She started singing in elementary school and later began to teach herself Japanese after watching the popular Japanese drama, Gokusen. As a teenager, Younha said she went to as many as 20 auditions with South Korean record labels but was rejected because she wasn’t “pretty enough to become a star.” As a result, she dropped out of high school at the age of 16 to pursue a singing career in Japan. Younha later attended Hankuk University of Foreign Studies, where she majored in Japanese.

After arriving in Japan in January 2004, Younha released her debut single, “Yubikiri,” that September, followed by the Japanese version of the song in October. Despite the fact the song was included on the soundtrack of the Fuji TV drama, Destiny of Love, it was not a success.

Despite the lackluster performance of her last 3 Japanese singles, Younha was chosen to sing an opening theme song for Kiba. The song “Hakanaku Tsuyoku” (儚く強く) was used as the second opening theme for the show. The single was released on January 17, 2007, and due to the nature of its tie-in, charted much higher than her last 3 releases, peaking at #36 – but also marked her last single with Epic Records.

Exactly two months after “Hakanaku Tsuyoku”, Younha returned to Korea to release her first Korean album entitled The Perfect Day to Say I Love You (고백하기 좋은 날, Gobaekhagi Jo-eun Nal). The album was a success, peaking at #1 on the charts. The first song promoted from the album was “Password 486”, for which she won the SBS Inkigayo Mutizen award twice. A music video was made for “Password 486”, which stars fellow Stam artist Yoon Ji-hoo. The album also features a collaboration with Wheesung. On July 14, 2007, Younha appeared on the Korean GomTV MSL Grand Finals (a StarCraft tournament) and performed in the opening ceremony. The second song promoted was “Love Condition”, accompanied with a repackage of her debut album. While no music video was made, the song was performed live a number of times, and had modest success on the charts.

At the 2007 MKMF held on November 17, 2007, Younha won the Best New Solo Artist award. With her increasing success, Younha released a version of Go! Younha rerecorded in Korean. The album, with minor track list changes, is titled Comet (혜성, Hyeseong) and was released on October 23, spawning two hit singles, the title track “혜성 (Hyeseong)” and “At First Sight”. Riding the success experienced in Korea, her very first Korean single “Audition” was re-released on March 14 as a physical CD, limited to 10,000 copies.

Epic Records quietly released a “best of” Japanese album/music video DVD of Younha’s work to date, SONGS -Teen’s Collection-, on March 26, 2008, signalling the end of her contract with the record label, due to the recent poor performance of her singles, and her focus on the Korean music industry.

On August 28, 2008 Younha followed up her last few successful albums with her sophomore effort, titled Someday. The album went on to spawn two hit singles, “Telepathy”, and “Gossip Boy”. The album also featured her second collaboration with Tablo, who co-wrote and featured in the song, “Memory”.

In early 2009, Younha made her comeback to the Japanese music industry, now signed with Sistus Records, with a Japanese version of “Memory”, titled “Kioku”, tying in as the ending theme to the Rideback anime. No physical release of the song was issued, and was an online only single until the release of her next studio album, Hitotsu Sora no Shita, which included it on the track listing. Her return to the industry also included a role in a Japanese movie, On Next Sunday (今度の日曜日に, Kondo no Nichiyoubi ni), released in April 2009, also singing the theme song On the Other Side of the Rainbow (虹の向こう側, Niji no Mukougawa). She went on to release 2 physical singles, “Girl” and “Sukinanda”, however both failed to chart in the top 100.

Her highly anticipated third album Part A: Peace Love & Ice Cream was released on April 16, 2009, with a new record label, Lion Media. The promotional track 1, 2, 3 was a signalled change in her style, in fashion sense, taking on a cuter, girly appearance, as opposed to her more tomboy look for her previous promotional periods. The style change also encompassed her music, with her songs from the album losing her trademark debut Piano rock sound which brought her critical acclaim and success, turning to pop. Despite the sudden change in musical style, the song was a strong contender for #1, but was beaten out due to strong competition during the promotional run.

On December 11, 2009, Younha released the second part of her third Korean album, Part B: Growing Season, showing a mature, darker contrast to the happier, pop-based Part A. The album spawned one #1 single, “We Broke Up Today”.

Her second Japanese album Under the Same Sky (ひとつ空の下) was released on September 22, 2010 in Japan and September 29, 2010 in Korea. The album features Younha’s work with i-dep and Sotte Bosse’s Nakamura Hiroshi, as well as popular acoustic guitar duo Depapepe. The album debuted to little fanfare, only achieving #169 on the Oricon Album charts.

On May 9, 2011, Younha became the 22nd host of MBC FM radio program, “Starry Night”. As of May 14, 2014, she is the current host of the program that has continuously run since 1969.

On July 12, 2011, it was revealed that Younha was suing her company, Lion Media, to request a termination of contract due to questionable validity, through the legal courts, though further revelations showed that these proceedings had started since April. A countersuit from her company was filed against her in return, for US$1 million to recover damages. A mediation session was scheduled for October to settle the matter, but fell through. It was not until February 2012, that the courts found the case in favor of Younha, resulting in the annulment of her contract with Lion Media, as well as 100 million KRW compensation.

After her legal troubles, Younha began her comeback activities with a new record label, wealive (now C9 Entertainment) . She released her fourth album Supersonic on July 3, 2012, featuring artists such as Jay Park, Tiger JK, and John Park. The album spawned two singles, the Top 10 Hit, Would We Have Changed? featuring John Park, and Run. The album was released to critical acclaim, embracing a rock based style, doing away with ballad styles she had promoted for the last 2 years, and even led to Run being nominated for Pop Song of the Year at the Korean Music Awards. She also joined the cast of I Am a Singer, a show based around professional singers remaking songs, ranging from old to current hits.

On May 2, 2013, Younha released her second EP, Just Listen receiving rave reviews. The album also brought her back to commercial success, “아니야 (Unacceptable)” became her first Top 5 single since “오늘 헤어졌어요 (Broke Up Today)” in 2009, and is also her first album to feature 2 Top 10 singles, Unacceptable and Reason.

On December 6, 2013, Younha released her third EP, Subsonic, featuring the lead-in single “It’s Okay” and follow up “Not There” featuring Eluphant. With the release of these singles, it brings about the first time in Younha’s career where she has achieved 3 Top 10 singles, and at a stretch, 4 Top 15 singles in one year.

On May 29, 2014, she collaborated with rock singer Jung Joon Young to release digital single “Just The Way You Are” (달리 함께). The song peaked at #11 on the Billboard K-pop Hot 100. She achieved her first #1 single in her career on the Gaon Charts, 10 years after debut, with her solo remake of her 2008 hit with Epik High, “Umbrella”. The original version in turn, also surged up the charts, jumping 245 places up to #53 in that same week. This marks the first time she has topped the chart since “Broke Up Today” 5 years ago, in 2009, and “Comet” in 2007.

On November 11, 2015, Younha released her single “Thinking About You” (널 생각해), produced by Lee Chanhyuk of Akdong Musician

She released her fifth album, RescuE, on December 27, 2017. Billboard ranked the album number eight on its list of top K-Pop albums of the 2010s, calling it “a cathartic listening experience that reflected on hard times and hinted to the brightness beyond them.”

Younha followed up by releasing the EP Stable Mindset in 2019, and then the EP Unstable Mindset on January 6, 2020. The latter contained the song “Winter Flower”, a collaboration with RM from BTS, which Billboard called “an epic, comforting power ballad”. Furthermore, the song gave Younha the title for the first Korean female solo artist to Top US iTunes chart.