Russians , Belarusians , and Ukrainians are East Slavic . Poles , Czechs , and Slovaks are West Slavic . Slavic peoples are classified into East Slavic ( including Russians , Ukrainians and Belarusians ) , West Slavic ( including Poles , Czechs and Slovaks ) , and South Slavic ( including Bulgarians , Serbs , Croats , Macedonians , Slovenes , Bosniaks and Montenegrins ) .