Kristjan is the spelling of the name Christian in Estonian language and Slovenian language.
People named Kristjan include:
- Kristjan Donaldson (born 1978), Australian Architect
- Kristjan Järvi (born 1972), Estonian-American conductor
- Kristjan Kais (born 1976), Estonian beach volleyball player
- Kristjan Kangur (born 1982), Estonian basketball player
- Kristjan Kasearu (born 1986), Estonian singer
- Kristjan Makke (born 1981), Estonian basketball player
- Kristjan Paapsi (born 1987), Estonian football player
- Kristjan Palusalu (1908–1987), Estonian heavyweight wrestler
- Kristjan Jaak Peterson (1801–1822), Estonian poet
- Kristjan Rahnu (born 1979), Estonian decathlete
- Kristian Rand (born 1987), Estonian ice dancer
- Kristjan Raud (1865–1943), Estonian painter and drawer
- Kristjan Tiirik (born 1982), Estonian football player
- Kristjan Fajt (born 1982), Slovenian professional road bicycle racer