Nikolai Alexeev graduated from the class of Mariss and Arvids Jansons at Leningrad Conservatoire in 1983 specializing in symphony orchestra conducting. He is the winner of Herbert von Karajan Conductors Competition (West Berlin, 1982), Václav Talich Conductors Competition (Prague, 1985) and Min-On Conductors Competition (Tokyo, 1985).
Nikolai Alexeev has been an assistant to Yuri Temirkanov, principal conductor of Leningrad Kirov Opera (now St Petersburg Mariinsky Theatre), chief conductor of Ulyanovsk Philharmonic Orchestra, chief conductor of Zagreb Philharmonic Orchestra, principal guest conductor of ERSO and Moscow Bolshoi Theatre. From 2000 he has been the conductor of St Petersburg Philharmonic Symphony Orchestra and Chamber Orchestra and from 2002 the principal guest conductor of Het Gelders Orkest (the Netherlands). From 2001–2010 he was the principal conductor of Estonian National Symphony Orchestra.
In addition to all major symphony orchestras in Moscow and St Petersburg, Nikolai Alexeev has conducted many well-known orchestras abroad, giving concerts in a number of cities in Europe, Japan and the United States.
Order of the White Star of the Third Class for advancement of Estonian musical life (2006),
People’s Artist of the Russian Federation (2007),
Cultural Award of the Republic of Estonia for creative accomplishments as the principal conductor and artistic director of ENSO (2010)