Stanislav Mostovoi was born in Leningrad into a family of musicians. He graduated with honors from the Choral College of the Academic Glinka Capella in 2000 and was admitted to the St Petersburg Conservatory named after Rimsky-Korsakov, from which he graduated in 2005.
From 2009 to 2012 he took a study course at the Opera Centre of Galina Vishnevskaya.
Mr. Mostovoi is a winner of the IV International Galina Vishnevskaya Competition of Opera Soloists (Third Prize and Audience Award, 2012.)
At the Galina Vishnevskaya Jubilee Performance he sang the part of Lenski in Tchaikovsky's Eugene Onegin (Theatre of Pierre Cardin, Paris, November 2011.) He also performed as Simpleton in Mussorgsky's Boris Godunov (The Hermitage Theatre, St Petersburg, December 2011.)
He has participated in master classes with famous musicians, such as Galina Vishnevskaya, Virgilijus Noreika, Mikhail Jurowski, Tito Capobianco, Cheryl Studer, Deborah York, Cheryl Milnes, Tamas Bator, Eugene Kohn, and Dmitry Bertman.
In April 2010, he appeared in concert performances of Pulcinella by Igor Stravinsky at The Great Hall of the Moscow Conservatory and Musica Viva by Alexander Rudin with the Moscow Chamber Orchestra.
In December 2011, he made his debut at the Bolshoi Theatre, performing the role of Simpleton in Boris Godunov by Mussorgsky.
In January 2012, he sang the part of Berendey in Rimsky-Korsakov's Snow Maiden as a guest soloist of the Bolshoi Theatre.
In April 2012, he sang The Young Gypsy (Aleko) at the Rakhmaninov Festival in Ivanovka.
In September 2012, he became a staff soloist of the Bolshoi Theatre.
In September 2012, Stanislav sang Il Duca di Mantua in Verdi's Rigoletto, conducted by Alexander Skulsky of the Nizhny Novgorod Philharmonic.
In January 2013, he took part in the premiere of Ravel's Child and the Spells, conducted by Alexander Soloviev of the Bolshoi Theatre.
In March 2013, he debuted as an Italian singer in Richard Strauss's Rosenkavalier, conductor Christoph-Mathias Mueller, Grand Theatre.
In 2014 he appeared as Simpleton in Boris Godunov at Salle Pleyel in Paris, conducted by Tugan Sokhiev, the Bolshoi Theatre's music director.
In 2016 he made his debut at the Mariinsky Theatre Concert Hall as Elvino (La sonnambula) and Tonio (La fille du regiment), with the Mariinsky Theatre's Zaurbek Gugkaev as conductor.