Martina Stoessel (Spanish: [maɾˈtina estoˈesel]; born 21 March 1997), known professionally as Tini, is an Argentine singer, actress, dancer and model. She began her career as a child actress, by appearing on the Argentine children's television series Patito Feo (2007). Tini rose to fame for her title role in the Disney Channel Latin America telenovela Violetta (2012–2015), which became an international success and established her as a teen idol. She achieved success on Latin American and European charts with multiple soundtracks, and reprised the character in the series' sequel film Tini: The Movie (2016).

In 2015, Tini became the first Argentine act to sign with Hollywood Records. She adopted her stage name and released her bilingual pop self-titled debut studio album (2016). The album debuted at number one in Argentina and reached the top ten in various European countries. After signing with Universal Music Latino, she explored Latin pop and reggae on Quiero Volver (2018), her second chart-topping album in Argentina. Tini re-calibrated her image from pop to reggaeton with the Latin trap-infused Tini Tini Tini (2020), which became the best-selling album by a woman in Argentina and the highest-certified female album, at double diamond, by the CAPIF. Shifting to Sony Music Latin and 5020 Records in 2021, she blended urbano and cumbia styles on Cupido (2023), which featured her first three Billboard Argentina Hot 100 number-ones: "Miénteme", "Bar", and "La Triple T". Certified diamond by the CAPIF, and double platinum (Latin) by the RIAA, the album was the first by an Argentine act in the 2020s decade to reach the top ten on the Billboard US Latin Pop Albums and top 50 on the US Top Latin Albums charts. It also made Tini the first Argentine woman to chart on the Billboard Global 200 and Global Excl. US. Themes of personal struggles and media scrutiny inspired the alternative pop album Un Mechón de Pelo (2024), which yielded the number-one single "Pa". Her guest appearance on "We Pray" in 2024 made her the first Argentine woman to appear on the US Billboard Hot 100.

Outside of music, Tini has played voice roles in dubbed versions of the animated films Monsters University (2013) and UglyDolls (2019). On television, she served as a judge and advisor on the Argentine (2018) and Spanish (2020) versions of The Voice, and lead the drama miniseries Breakdown (2025).

One of the best-selling Argentine music artists, Tini is among the highest-grossing Argentine touring acts, and is the second-most-streamed Argentine female act. Her accolades include five Gardel Awards, one Lo Nuestro Award, three Bravo Otto Awards, two Martín Fierro Awards, two Los 40 Music Awards, three MTV Millennial Awards, and two MTV Europe Music Awards. In 2016, Tini was named among The Hollywood Reporter's 25 Most Powerful Women in Global Television. From 2018 to 2020, she was named Billboard Argentina's "Artist of The Year" and was the most-streamed Argentine woman on Spotify for each year, consecutively. She was the first artist to sell out nine consecutive concerts at the Estadio Luna Park and six consecutive concerts at the Hipódromo Argentino de Palermo. In 2021, Tini was included in ¡Hola!'s list of Top 100 Latina Powerhouse women; from 2019 to 2022, she was named as one of the ten most influential women from Argentina. In 2025, she made it to the Madame Tussauds Hot 100 list, recognizing her as a Latin pop innovator.

Stoessel was born in Buenos Aires, the daughter of Mariana Muzlera and television director and producer Alejandro Stoessel. She has a brother, Francisco, who is one year older than her. Stoessel began her artistic training at a young age studying singing, piano, musical comedy, musical theater, and dance in her native Buenos Aires. Stoessel was educated at two private bilingual schools: Colegio San Marcos and Colegio Martín y Omar de San Isidro.

In 2007, Stoessel had a role in the first season of the popular Argentine children's telenovela, Patito Feo, as "Martina", one of Fito Bernardi's assistants. She also played the role of "Anna" in a flashback episode in the same series. In 2011, Stoessel recorded the Spanish version of the Shannon Saunders' song, "The Glow", called "Tu Resplandor"; the song was included on the album, Disney Princess: Fairy Tale Songs. She performed the song at an event for Disney Channel Latin America called Celebratón on 31 December 2011. The song was later released on an album for the series in March 2012.

Stoessel's father presented an unrelated project to Disney Channel producers, who later informed him about auditions for the lead role for the network's upcoming television series, Violetta. In late 2011, after an intense casting process, Stoessel obtained the principal role in the series, a tween-oriented musical series developed as a co-production between Disney Channel Latin America, Europe, Middle East and Africa. The show's first season began production in Buenos Aires in 2012. Stoessel played the titular character, Violetta Castillo, during all three seasons of the show. She sang the series' theme song, "En Mi Mundo", which was later released as a single on 5 April 2012 to promote the show. The song appeared on the first Violetta soundtrack album, which was released in June 2012. Subsequently, she recorded the Italian version, "Nel Mio Mondo" and the English version, "In My Own World". For the role, Stoessel won an award for "Female Newcomer" in the 2012 edition of the Kids' Choice Awards Argentina and was also nominated for the U.S. version, the Nickelodeon Kids' Choice Awards, in the category "Favorite Latin Artist".

From July 2013 to March 2014, Stoessel and the cast of Violetta embarked on their first concert tour, Violetta en Vivo, visiting Latin America and Europe, in support of the series and its albums. It became one of the highest-grossing concert tours among South American acts and in 2014, grossing over US$17.5 million and selling over 1.7 million tickets across 50 reported shows of 200 shows. Stoessel appeared on the third Violetta soundtrack album, Hoy somos más, released in June 2013. On 10 August 2013, she performed, along with the cast of Violetta, at the UNICEF television charity event Un sol para los chicos, where she sang the songs, "Ser Mejor" and "En Mi Mundo". In 2013, she recorded "Libre Soy" and "All'Alba Sorgerò", the Latin American Spanish and Italian versions of the pop version of "Let It Go", the closing credits song from the Disney animated film Frozen. These versions of the song were used in the film's ending credits in US. In November 2013, Stoessel was included in the fourth Violetta soundtrack, Violetta en Vivo. It features songs from the first two seasons of Violetta, and songs from the Violetta en Vivo tour.