Janko is a name that derives from a diminutive form of the name Jan (Slavic languages), Janez (Slovenian), János (Hungarian), and Yakov/Jacob (Ashkenazi Jewish). It also derives from the vernacular form of Latin Johannes.^[1] Notable people with the name include:

• Janko Benša (born 1977), Serbian distance runner
• Janko Bobetko (1919–2003), Croatian general
• Janko Brašić (1906–1994), Serbian naïve painter
• Janko Drašković (1770–1856), Croatian politician
• Janko Dreyer (born 1994), South African cricketer
• Janko Gagić (died 1804), Serbian hajduk leader
• Janko Gojković (born 1973), Bosnian swimmer
• Janko Gredelj (1916–1941), Yugoslav communist
• Janko Halkozović (fl. 1757), Serbian painter
• Janko Janša (1900–?), Slovenian cross-country skier
• Janko Jesenský (1874–1945), Slovak lower nobleman and member of the Slovak national movement
• Janko Kamauf (1801–1874), city magistrate of Gradec and mayor of Zagreb, Croatia
• Janko Kersnik (1852–1897), Slovene writer and politician
• Janko Kobentar (born 1940), Slovenian cross-country skier
• Janko Konstantinov (1926–2010), Macedonian architect and artist
• Janko Kos (born 1931), Slovenian literary historian
• Janko Lavrin (1887–1986), Slovene novelist, poet, critic, translator, and historian
• Janko Leskovar (1861–1949), Croatian novelist
• Janko Lukovski (1946–2023), Macedonian basketball player and coach
• Janko Mavrović (born 1977), Croatian team handball player
• Janko Mežik (1921–1998), Slovenian ski jumper
• Janko Mihailović Moler (1792–1853), Serbian priest and artist
• Janko Neuber (born 1971), German cross-country skier
• Janko Nilović (born 1941), pianist, arranger, and composer
• Janko Orožen (1891–1989), Slovene historian and schoolteacher
• Janko Pacar (born 1990), Swiss footballer
• Janko Pleterski (1923–2018), Slovenian historian, politician, and diplomat
• Janko Popović Volarić (born 1980), Croatian actor
• Janko Premrl (1920–1943), Slovene Partisan
• Janko Prunk (born 1942), Slovenian historian
• Janko Sanković (fl. 1963–1978), Yugoslavian football goalkeeper
• Janko Simović (born 1986), Montenegrin footballer
• Janko Smole (1921–2010), Slovenian politician
• Janko Tipsarević (born 1984), Serbian tennis player
• Janko Tumbasević (born 1985), Montenegrin footballer
• Janko Veber (born 1960), Slovenian politician
• Janko Veselinović (lawyer) (born 1965), Serbian academic and politician
• Janko Veselinović (writer) (1862–1905), Serbian writer
• Janko Vranyczany-Dobrinović (1920–2015), Croatian politician and diplomat
• Janko Vukotić (1866–1927), Montenegrin general
• Janko Vuković (1871–1918), Croatian admiral
• Janko Vučinić (1966–2019), Montenegrin professional boxer and politician
• Janko Šimrak (1883–1946), Croatian Greek Catholic hierarch
• Janko Štefe (1923–?), Slovenian alpine skier

• Anna Janko (born 1957), Polish poet, writer, columnist and literary critic
• Eva Janko (born 1945), Austrian javelin thrower
• Lubomír Janko (born 1955), Czech rower
• Marc Janko (born 1983), Austrian footballer
• Paul von Jankó, Hungarian inventor of the Jankó keyboard
• Richard Janko, British-American classicist
• Saidy Janko (born 1995), Swiss footballer
• Sepp Janko (1905–2001), Volksgruppenführer and SS Obersturmführer
• Zvonimir Janko (1932–2022), Croatian mathematician