Alexander Gerasimov was born in St Petersburg and studied at the St Petersburg State Rimsky-Korsakov Conservatoire. He was a soloist with the Mariinsky Academy of Young Singers from 2000 to 2008, when he joined the Mariinsky Opera Company.

His repertoire includes:
Mitukha, Jesuit (Boris Godunov)
Captain, Zaretsky (Eugene Onegin)
Ivan Zhuran (The Enchantress)
Second Herald, Shrovetide (The Snow Maiden)
Panas (Christmas Eve)
Old Mighty Bogatyr (Sadko)
Second Shipmaster (The Tale of Tsar Saltan)
Tsarevich Afron (The Golden Cockerel)
Aleko (Aleko)
Potapych (The Gambler)
Farfarello (Love for Three Oranges)
Tsarev (Semyon Kotko)
Matveyev, General Belliard, General Rayevsky (War and Peace)
Surgeon, Correspondent (The Story of a Real Man)
Ivan Ivanovich, Speculator, Janitor (The Nose)
Steward, Non-Commissioned Officer (Katerina Ismailova)
Afanasy Ivanovich (Moscow, Cheryomushki)
Grigory, Trifon Borisovich (The Brothers Karamazov)
Procurator (Dead souls)
Monk (Don Carlo)
Count Monterone (Rigoletto)
Betto di Signa (Gianni Schicchi)
Talpa (Il tabarro)
Schaunard (La bohème)
Bonze (Madama Butterfly)
Bernardino (Benvenuto Cellini in concert)
Brander (La damnation de Faust in concert)
Second Philistine (Samson et Dalila)
Ramiro (L'Heure espagnole)
Orator, Priest, Second Man (Die Zauberflöte in concert)
Alberich (Das Rheingold)
Old Peasant (Jenůfa).

Alexander Gerasimov has toured with the Mariinsky Opera Company in Finland, Sweden, France, the USA, Japan and Germany.

He has taken part in the Aix-en-Provence music festival (Love for Three Oranges).
In 2004 he took part in a new production of Shostakovich's Moscow, Cheryomushki at the Opéra de Lyon (France).