Kim Tae-yeon (Korean: 김태연; born March 9, 1989), known mononymously as Taeyeon, is a South Korean singer. She debuted as a member of girl group Girls' Generation in August 2007, which went on to become one of the best-selling artists in South Korea and one of the most widely known K-pop groups worldwide. She has since participated in other SM Entertainment projects, including Girls' Generation-TTS, SM the Ballad, Girls' Generation-Oh!GG, and the supergroup Got the Beat.

In 2015, Taeyeon released her debut extended play (EP) I, whose titular single reached number one on South Korea's Gaon Digital Chart. In 2016, she released the number-one single "Rain" as part of the SM Station project, followed by her second EP Why, which peaked atop the Gaon Album Chart. Taeyeon's debut studio album, My Voice, was released in 2017 and yielded the top-five singles "11:11", "Fine" and "Make Me Love You". Taeyeon ventured into the Japanese music scene in 2018 with the digital single "Stay", followed by the 2019 EP Voice. Her second studio album, Purpose (2019), featured the number-one single "Four Seasons" and the top-5 single "Spark". Her third studio album INVU (2022) included the number-one titular single as well as top-10 singles "Weekend" and "Can't Control Myself".

On television, Taeyeon appeared on the reality shows We Got Married (2009) and Begin Again (2019) and hosted Queendom 2 (2022). She is currently a cast member of Amazing Saturday (2020–present). Additionally, Taeyeon has recorded soundtracks for various television dramas and films, including "If" for Hong Gil-dong (2008), "Can You Hear Me" for Beethoven Virus (2008), and the chart-topping "All About You" for Hotel del Luna (2019).

Having sold over one million physical albums and twenty million digital singles as of 2021, Taeyeon is one of the best-selling solo artists in South Korea. She has received various awards and nominations, including seven Golden Disc Awards, six Seoul Music Awards, five Circle Chart Music Awards, four Melon Music Awards, and four Mnet Asian Music Awards.

Taeyeon was born on March 9, 1989, in Wansan District, Jeonju, South Korea. Her family consists of her parents, an older brother, and a younger sister Kim Hayeon, who made her solo debut in 2020. Having believed that she was "only talented" at singing, Taeyeon first dreamed of becoming a singer at a young age. During her second year in middle school, Taeyeon accompanied her father to SM Academy, a former music institution and auxiliary affiliation of SM Entertainment, to pursue vocal lessons. Although at the time her father did not encourage Taeyeon to become an entertainer, he was persuaded by the school's principal to give his daughter a chance after she recognized Taeyeon's "clean" voice. During the next year, Taeyeon accompanied her father from their hometown to Seoul every Sunday to receive vocal lessons from The One. She named BoA, Whitney Houston and Hikaru Utada as her pre-debut inspirations.

Taeyeon trained under The One for three years. In a 2011 interview, he described Taeyeon as a "smart" student, someone "unlike others who came to him with dreams of becoming a celebrity... [she] wanted to be a singer and reach the top with her own talents." In 2004, he "wanted to acknowledge Taeyeon's potential" by giving her the chance to be in his song "You Bring Me Joy". That same year, she won first place at the SM Youth Best Competition and signed a contract with SM Entertainment. The training process was so tough that she almost quit at one point; she persisted, however, and debuted as a member of girl group Girls' Generation in August 2007. Both the president of SM Academy and The One later named Taeyeon as one of their most memorable students. Taeyeon graduated from Jeonju Art High School and was awarded the school's Lifetime Achievement Award in 2008.

Taeyeon sang "7989" (featuring Kangta), a track from both Girls' Generation's eponymous debut album (2007) and Kangta's fourth studio album, Eternity (2008). Taeyeon began to gain popularity through her various television soundtrack releases, recording "If" for the KBS2 drama Hong Gil Dong (2008) and "Can You Hear Me" for MBC's drama Beethoven Virus (2008). "If" was later deemed more popular than its respective drama, and "Can You Hear Me" won a Popularity Award at the 2008 Golden Disk Awards. Both tracks remain among Taeyeon's most well-known hits. During this period, she also recorded "It's Love", a duet with Girls' Generation member Sunny, for the MBC drama Heading to the Ground (2009).

Following a radio hosting job in 2009–10, Taeyeon journeyed into acting, making her theatrical debut in a lead role in the 2010 musical A Song to the Sun. She played the part of Kaoru Amane, a teenager who suffered from xeroderma pigmentosum, and learned to play a guitar for the role. Her performance in the sold-out shows received good press despite the musical's critical reviews of the musical itself. Jang Gyeong-jin of 10Asia praised Taeyeon's "distinct vocals" and commented that her acting stood out among idol stars who had ventured into musical theatre, while Kim Ji-yeong from The Dong-A Ilbo felt "Taeyeon's optimistic and charming personality made her the perfect match" for the role. Despite the favorable response, Taeyeon later described musicals as difficult, stating that her weak concentration made it hard for her to act and sing at the same time.