Alonso is best known for her lead role as "Angie Carrara" in the Disney Channel Latin America Series, Violetta.

At 8, she quit field hockey and asked her parents to enroll her in musical comedy classes at "Broadway Street", an acting school in Haedo, Buenos Aires.

She unsuccessfully auditioned for spot in a season of Latin American Idol[5] before later attending castings in 2007 for High School Musical: La Selección.

Subsequently, she was also cast in her first acting role as "Clari" in the Argentine film version of High School Musical.

On 21 October 2008, during a taping of "Zapping Zone", Alonso premiered her debut single, "A mi alrededor" with the collaboration of Sophie Oliver Sanchéz.

[8] That same year she began working as a voice-over actress on the Spanish-language version of the Disney Channel series Pecezuelos.

[9] In August 2010, she traveled to São Paulo, Brazil to shoot a two-part episode for the Disney Channel series, "Cuando toca la campana", which is based on the original US version, As the Bell Rings.

The television series was an international hit and aired in several countries on Disney Channel networks across Europe, Africa, Australia, and New Zealand.

On 21 March 2014, Alonso confirmed with fans via her official Twitter account that she would continue playing "Angie" for the third season of Violetta.

[17] For one week in mid-January 2015, Alonso filmed the second season of Angie e le ricette di Violetta in Milan, Italy.

Following the conclusion of production on the series, she revealed to fans via her official Facebook page that the show marked her final project with Disney after an eight-year career with the network.

[18] In June 2015, she shot the Spanish-language short film, Jazmin de invierno ("Jasmine's Winter" in English) in Buenos Aires.

In mid-July, she travelled to Rome, Italy to begin filming the web series, Lontana da me ("Far away from me" in English).

[21][22][23][24] For several days in early February 2017, Alonso filmed the short movie, "Insane Love", directed by Italian filmmaker, Eitan Pitigliani, in Rome, Italy.

[25] In late July 2017, she travelled to Rome to begin filming the Italian comedy movie, "Il Tuttofare".

[26][27] Later that year, Alonso was cast in the Spanish web mini-series, "In the Mood"; the program's first season consisted of four episodes and premiered on YouTube on August 30, 2017.

[28] In early March 2018, Alonso filmed a small role in the Spanish drama movie, "@buelos", in Madrid.

[29] She was also cast in the Spanish one act play, "La memoria", which ran for 15 minutes showings in Madrid in late April for several days.

[30] In May 2018, it was announced that Alonso had been cast in a role in the upcoming Argentine crime television series, "Campanas en la noche".

In 2022, she was cast in the Uruguayan drama, Milgona, and later appeared in a small role in the 2024 comedy film, No puedo vivir sin tí.

[36] The film was popular upon its August 2024 release on Netflix, obtaining a top 10 placement on the streaming service's platform in Argentina.

[37] In 2025, Alonso announced via her official Instagram account that she had begun rehearsals for the Argentine play, Match 4 Love.

[38] On 26 January 2015, Alonso was announced as a contestant on third season of the reality competition Notti sul ghiaccio ("Nights on Ice" in English) for the Italian network Rai 1.

She moved back to Buenos Aires in May 2018, following her casting in the Argentine TV show, "Campanas de la noche".