Leonhard Euler (/ˈɔɪlər/ OY-lər,[2] German: [ˈɔʏlɐ] ;[a] 15 Epulelo mu 1707 – 18 Sekutembala 1783) wakaŵa wa masamu,wa vyakuthambo,vya kayendelo ka chalo na wakunozga vinthu wakufumila mu chalo cha Switzerland.