Željko or Zeljko (Cyrillic script: Жељко) is a Slavic masculine given name. Notable people with the name include:
Željko Čajkovski (born 1925), Croatian football (soccer) player and coach
Željko Đokić (born 1982), Serbian footballer
Željko Šašić (born 1969), Serbian pop-folk singer
Željko Šturanović (born 1960), former Prime Minister of Montenegro who served from 2006 to 2008
Željko Adžić (born 1965), former Croatian footballer
Željko Bebek (born 1945), popular Bosnian singer, lead vocalist of Bijelo dugme from 1974 to 1984
Željko Blagojević, Bosnian Serb runner who ran over 900 km from Banja Luka, Bosnia to Kosovo as a protest
Željko Božić (born 1974), famous Serbian stuntman and actor
Željko Bogut (born 1969), Bosnian chess player and two time national champion
Željko Brkić (born 1986), Serbian football goalkeeper
Željko Cicović (born 1971), Serbian football goalkeeper
Željko Đurđić (born 1961), Serbian handball goalkeeper
Željko Filipović (born 1988), Slovenian footballer
Željko Franulović (born 1947), former Croatian tennis player
Željko Ivanek (born 1957), Emmy-award winning Slovenian American actor
Željko Ivanković (born 1954), Croatian writer from Bosnia and Herzegovina
Željko Janjetović, Bosnian diplomat, Ambassador Extraordinary and Plenipotentiary of Bosnia and Herzegovina to the Russian Federation
Željko Joksimović (born 1972), popular Serbian singer, songwriter and producer
Željko Kalac (born 1972), Australian goalkeeper currently playing for Greek club Kavala
Željko Kalajdžić (born 1978), Serbian professional football midfielder
Željko Kerum (born 1960), Croatian entrepreneur and politician
Željko Komšić (born 1964), Bosnian-Herzegovinian politician
Željko Kopanja (born 1954), Bosnian Serb newspaper editor and director of Nezavisne Novine
Željko Kovačević (born 1981), Serbian footballer
Željko Krajan (born 1979), Croatian tennis coach and former professional tennis player
Željko Kuzmić (born 1984), Serbian professional football goalkeeper
Željko Lelek (born 1962), Bosnian Serb indicted for mass rape crimes in Višegrad during the Bosnian War
Željko Ljubenović (born 1981), Serbian football midfielder
Željko Lordanić (born 1948), Croatian cartoonist, animator and illustrator
Željko Malnar (1944–2013), writer and TV presenter
Željko Matuš (born 1935), former Croatian footballer
Željko Mavrović (born 1969), retired male boxer from Croatia turned entrepreneur
Željko Mijač (born 1954), Croatian football manager and former player
Željko Milinovič (born 1969), former Slovenian footballer
Željko Milošević (born 1976), Serbian footballer
Željko Mitrakovič (born 1972), Slovenian football midfielder
Željko Mrvaljević (born 1981), Montenegrin football defenderer
Željko Nimš (born 1950), Croatian handball player
Željko Obradović (born 1960), professional basketball coach and former professional basketball player
Željko Pahek (born 1954), Croatian and Serbian comics creator and illustrator
Željko Pavlović (born 1971), Croatian football goalkeeper
Željko Perušić (born 1936), former Croatian footballer
Željko Pervan (born 1962), Croatian comedian
Željko Petrović (born 1965), retired footballer from Montenegro, technical coach of Feyenoord Rotterdam
Željko Polak (born 1976), retired Bosnian Serb football player
Zeljko Ranogajec, professional gambler from Australia
Željko Ražnatović (1952–2000), Serbian career criminal and later a paramilitary leader
Željko Rebrača (born 1972), retired Serbian professional basketball player
Željko Rohatinski (born 1951), current Governor of the Croatian National Bank
Željko Samardžić (born 1955), Bosnian Serb pop-folk singer
Željko Senečić (born 1933), Croatian film and television production designer, film director and screenwriter
Željko Sošić (born 1980), young Montenegrin director
Željko Sopić (born 1974), Croatian football midfielder
Željko Srdić (1977), Serbian contemporary hyperrealist artist and comic book artist
Željko Stinčić (born 1950), former Croatian footballer
Željko Tadić (born 1974), former Montenegrin footballer
Željko Tanasković (born 1967), Serbian volleyball player
Željko Turk (born 1962), the current mayor of Zaprešić, a town in Zagreb County, Croatia
Željko Vincek (born 1986), Croatian sprinter who specializes in the 400 metres
Željko Vuković (footballer, born 1962), Croatian-born Austrian footballer
Željko Vuković (footballer, born 1963), Montenegrin footballer
Željko Zagorac (born 1981), professional basketball player
Zeljko Babic (born 1976), former association football player in the now defunct National Soccer League in Australia
Zeljko Bilecki (born 1950), retired Canadian soccer player
Zeljko Gavrilović (born 1971), veteran Serbian footballer
Zeljko Loparić (born 1939), Croatian philosopher, historian of the philosophy and university teacher
Zeljko Marasovich, Croatian American composer of classical and film music
Zeljko Radovic (Austrian footballer) (born 1974), Austrian football player