Niclas may refer to:

• Niclas Alexandersson (born 1971), retired Swedish football midfielder
• Niclas Andersén (born 1988), Swedish ice hockey player
• Niclas Bendixen, Danish actor, dancer and choreographer
• Niclas Edman (born 1991), Swedish ice hockey player
• Niclas Fasth (born 1972), Swedish professional golfer
• Niclas Frisk (born 1969), Swedish musician
• Niclas Füllkrug (born 1993), German association footballer
• Niclas Hävelid (born 1973), professional ice hockey defenceman
• Niclas Huschenbeth (born 1992), chess grandmaster.
• Niclas Jensen (born 1974), Danish professional football player
• Niclas Jönsson (born 1967), former driver in the Indy Racing League
• Niclas Kindvall (born 1967), retired Swedish football player
• Niclas Levein (born 1988), retired Swedish ice hockey player
• Niclas Lucenius (born 1989), Finnish professional ice hockey center
• Niclas Olofsson (born 1975), former floorball goalkeeper
• Niclas Rasck (born 1969), former Swedish football defender
• Niclas Sahlgren (1701–1776), Swedish merchant and philanthropist
• Niclas Wallin (born 1975), professional ice hockey player
• Niclas Weiland (born 1972), retired German football player
• Niclas, Graf von Abensberg (1441–1485), knight and nobleman under the reign of Louis IX, Duke of Bavaria-Landshut
• Niclas Jonasson (born 1976), Swedish orienteering competitor and world champion

• Abraham Niclas Edelcrantz (1754–1821), Finnish born Swedish poet and inventor
• Jacob Niclas Ahlström (1805–1857), Swedish Kapellmeister and composer
• Johan Niclas Byström (1783–1848), Swedish sculptor

• Thomas Evan Nicholas (Niclas y Glais) (1879–1971), Welsh language poet, preacher, radical and champion of the disadvantaged of society