Kammala jumla mai zuwa: A Wasannin Olympics na bazara na 2012 a London, Sjöström ya yi gasa a cikin wasanni guda hudu, ya kai wasan kusa da na karshe na 50 m freestyle, 100 m freestyle da 200 m freestyle, kuma ya gama 4th a wasan karshe na
100 m butterfly a cikin lokaci na 57.17. Dana Vollmer ta Amurka ta karya rikodin duniya na Sjöström a cikin wannan tseren. A cikin 2015 duk da haka Sjöström ya dawo da tarihin duniya ta hanyar inganta shi sau biyu a Gasar Cin Kofin Duniya a Kazan.