Joel Basman was born in Zurich on January 23, 1990. As a teenager, he made his first acting experiences in youth theatre projects at the city's Schauspielhaus. In 2004 – at the age of 14 – he was cast for the Swiss TV series "Lüthi und Blanc", in which he played the character of Zizou until 2006. Also in 2004, he made his screen debut in the award-winning comedy "Mein Name ist Eugen". This was followed by roles in several TV and film productions, including "Cannabis – Probieren geht über Regieren" (CH 2006) and "Tausend Ozeane" (CH/LU 2008). Basman's portrayal of an autistic person in the made-for-TV drama "Jimmie" (CH 2008) garnered him rave reviews and the Actor's Award at the Festival "Cinéma Tout Ecran" in Geneva.

At the 2008 Berlin IFF, he was named the Swiss Shooting Star for his performance in the drama "Luftbusiness". Basman also got a lot of attention – and won the Günther Strack Award – for his role in the controversial "Picco", in which he plays a young prisoner who is eventually tortured to death by his cellmates. After starring in the coming-of-age story "Songs of Love and Hate" (CH 2010), Basman played a killer in the thriller "Wer ist Hanna?" ("Hanna", USA/UK/DE 2011) and a crook in the children's film "Löwenzahn - Das Kinoabenteuer". He also had a supporting role in the successful TV miniseries "Unsere Mütter, unsere Väter" ("Generation War", 2012).

Hailing from a family of designers, Basman presented his first own fashion collection in September 2013. After a small turn as a soldier in George Clooney's WWII drama "Monuments Men" (USA/DE) he played a paraplegic who robs a gas station in order to prove his love for a girl in the comedy "Vielen Dank für Nichts" in 2014.

Basman next had leading roles in the international co-production "Dawn" (2014) and the Swiss TV movie "Ziellos" (2014). He starred opposite Jonas Nay in the acclaimed drama "Wir sind jung. Wir sind stark" ("We Are Young. We Are Strong", 2014), which depicts the violent assault on asylum seekers by frustrated youths in East Germany in 1992. His performance garnered Basman the German Film Award for Best Supporting actor. Following his turn as a junkie in the "Tatort" episode "Borowski und der Himmel über Kiel" (2015, TV), he was one of the leads in Andreas Dresen's adaptation of the bestselling novel "Als wir träumten" ("As We Were Dreaming").

The same year, he won a Swiss Television Award for his performance in "Ziellos" and was one of the leads in the Academy Award-nominated drama "Unter dem Sand – Das Versprechen der Freiheit" ("Land of Mine", DK/DE). Following a supporting role in the thriller "Late Shift" (CH/GB 2016), he played poet Rainer Maria Rilke in Christian Schwochow's period drama "Paula" (DE/FR 2016). After turns in the "Tatort" episode "Kriegssplitter" (2017) and in "Es war einmal in Deutschland..." ("Bye Bye Germany", DE/BE/LU 2017). Basman was one of the leads in the coming-of-age drama "Es war einmal Indianerland" ("Once Upon A Time in Indian Country").

In 2019, Basman had small supporting roles in Terrence Malick's historical drama "A Hidden Life," which premiered at the Cannes Film Festival in May of that year, and Savaş Ceviz's pedophilia drama "Kopfplatzen" ("Head Burst"), starring Max Riemelt, which premiered at the International Film Festival in Hof in 2019 and was released in German theaters in August 2020. A year later, no fewer than four theatrical productions were released with Basman in supporting roles: in Tim Fehlbaum's dystopian science fiction thriller "Tides" (DE CH), which premiered at the Berlinale, he played the right-hand man of a camp director, in Philipp Stölzl's film adaptation of the literary classic "Schachnovelle" ("The Royal Game"), which was awarded the Gilde Film Prize for Best Film (national) at the Leipzig 2021 Film Art Fair, he plays the bartender Willem, and in the biographical portrait of the writer, director and provocateur Thomas Brasch he took on the role of his brother Klaus. Finally, in December of that year, "Monte Verità - Der Rausch der Freiheit" ("Monte Verità", CH AT DE) had its theatrical release. In this historical drama about a mother of two who emancipates herself from her oppressive bourgeois environment and her sexually abusive husband and discovers her talent for photography, Basman played the writer Hermann Hesse. Also in December, ARD aired Julia von Heinze's miniseries "Eldorado KaDeWe," set in 1920s Berlin, in which he stars as the son and heir of German Jewish KaDeWe founder Abraham Adolf Jandorf, who is at odds with his father and seeks to alleviate his wartime traumas through drugs and a sadomasochistic relationship with a brothel owner.  

Also in 2021, Joel Basman stood in front of the camera as a convicted family man and lover of Katja Riemann's main character for the thriller miniseries "Der Überfall," which aired on ZDF in March 2022. Already in January 2022, the British-US agent film "The King's Man," which had already been filmed in 2019, was released in theaters. In the prequel to the Kingsman film series starring Ralph Fiennes, he played the assassin Gavrilo Princip, who was instrumental in starting World War I by murdering the heir to the Austro-Hungarian throne Franz Ferdinand and his wife Sophie. Also in 2022, the film "Bis wir tot sind oder frei" ("Caged Birds"), which had already been screened at festivals in 2020, was released. In this film Basman plays the leading role of the prominent Swiss professional criminal and "breakout king" Walter Stürm.