Nikolai Alexandrovich Berdyaev (/bərˈdjɑːjɛf, -jɛv/; Russian: Никола́й Алекса́ндрович Бердя́ев; March 18 O.S. March 6] 1874 – March 24, 1948) was a Russian political and also Christian religious philosopher who emphasized the existential spiritual significance of human freedom and the human person. Alternate historical spellings of his name in English include "Berdiaev" and "Berdiaeff", and of his given name as "Nicolas" and "Nicholas".

Nikolay or Nikolai is an East Slavic variant of the masculine name Nicholas, meaning "victory of the people." Kolya is a short name of Nikolay.

Nikolai Valuev vs. Evander Holyfield was a professional boxing match contested on December 20, 2008 for the WBA heavyweight championship.