Andrej is a variation (Czech and Slavic) of Andreas.
Andrej is also a variation (Czech, Russian, and Slavic) of the name Andrew (English, Greek, and Russian).
Andrei (English, Russian, Romanian, Slavic, and Ukrainian variant spelling) is a form of Andrej.
Andrej is unusual as a baby name for boys. It is not listed in the top 1000 names. Among the group of boy names directly linked to Andrej, Andrew was the most regularly used in 2018.
† English pronunciation for Andrej: AE as in "at (AE.T)" ; N as in "knee (N.IY)" ; D as in "day (D.EY)" ; R as in "race (R.EY.S)" ; EY as in "ate (EY.T)"