Daniel Sträßer was born in Völklingen in 1987. He started acting in the theatre group of his Waldorf school. From 2007 to 2011 he studied acting at the Mozarteum Salzburg. As a student he took part in several stage productions and in 2011 he appeared at the Salzburg Festival in "A Midsummer Night's Dream". Also in 2011 (even before he graduated) he was discovered by the chief dramaturge of the Vienna Burgtheater at the Hamburg Young Talent Competition. In the same year he made his debut there as Romeo in "Romeo and Juliet" - and received a nomination for the 2012 Nestroy Theatre Prize for Best Young Actor.  

Sträßer had further roles at the Burgtheater, among others in "Hamlet" (2013, as Rosenkranz) and in "Wunschloses Glück" (2014, as Peter Handke). For his impersonation of Constantine in Chekhov's "The Seagull" (2015) at the Burgtheater's Akademietheater, Sträßer was again nominated for the Nestroy Theatre Prize, this time as Best Actor.   
Daniel Sträßer made his debut as a film actor in 2014 in the Austrian production "Der letzte Tanz". Alongside Erni Mangold, he played the leading role of a community service worker who develops an emotional and ultimately sexual relationship with an Alzheimer's patient. For this he is arrested, accused of rape and convicted. The film received several awards, Sträßer was nominated for Best Actor at the Austrian Film Award 2015.   

In Sylke Enders' coming of age story "Schönefeld Boulevard" (2014) he played the sarcastic buddy of an introverted 18-year-old outsider. Christian Petzold cast him as the suspicious son of a murder victim in the "Polizeiruf 110" episode "Kreise" (2015); in Christian Schwochow's Ken Follett film adaptation "Die Pfeiler der Macht" ("A Dangerous Fortune", 2016, TV) he belonged to the core cast as the main character's cousin.   

Strasser embodied historical personalities in "Egon Schiele - Tod und Mädchen" ("Egon Schiele: Death and the Maiden", AT 2016; as Schiele's close friend Erwin Dom Osen) and "Lou Andreas-Salomé" ("Lou Andreas-Salomé, The Audacity to be Free", DE/AT/CH/IT 2016, as physician Friedrich Pineles). In the successful TV series "Charité" (2017) he also played a historical figure, the judge and politician Heinrich von Minckwitz.   

In addition to his film and television work, Sträßer also remained active as a stage actor, with engagements at the Staatsschauspiel Dresden (2016) and the Schauspielhaus Zurich (2017-2018), among others.   

Since 2020, Sträßer has been appearing in "Tatort" episodes from Saarbrücken playing an investigator alongside Vladimir Burlakov. On the big screen Sträßer appeared in Visar Morina's bullying drama "Exil" ("Exile", BE/DE/XK) in a smaller supporting role and played a leading role in the award-winning relationship story "La Palma", about a couple who start a bizarre role-play during a vacation. In 2021, "A Pure Place" opened in cinemas, with Sträßer as a member of a bizarre sect.