Alexander Mikhniuk finished Novopolotsk State Music School where he had majored in chorus conducting.
In 2015, he graduated in voice from the Belarusian State Academy of Music (class of V.Klindukhov).
Still a student, he took part in two productions, namely Eugene Onegin by Pyotr Tchaikovsky as Vladimir Lensky and Don Pasquale by Gaetano Donizetti as Ernesto.
He joined the opera company of the Bolshoi Theatre of Belarus in 2015.
He is prolific on the concert platform and often appears in concerts at the Bolshoi Theatre of Belarus and the Belarusian State Philharmonic Hall.
In 2018, Alexander Mikhniuk made his debut with the Azerbaijan State Academic Opera and Ballet Theatre as Rodolfo in La bohème by Giacomo Puccini (conductor Javanshir Jafarov).
He performed a solo tenor role in Giuseppe Verdi’s Requiem at the Jan Kiepura International Festival in Krynice, Poland (conductor Stanisław Krawczyński).
In October 2018, he performed the role of Lensky in Eugene Onegin in Haifa, Israel (conductor Viktor Ploskina, director Oksana Taranenko).
In November 2018, he made his debut as Rinuccio in Puccini’s Gianni Schicchi at the opera festival dedicated to the 160th anniversary of Giacomo Puccini’s birth held in Samara, Russia (conductor Evgeny Khokhlov, director Nadezhda Bakhshieva).
In 2019, Alexander Mikhniuk took part in the Chinese tour of the State Academic Symphony Orchestra of the Republic of Belarus under the baton of Igor Bukhvalov.
In October 2022, he performed the role of Svetsilovich in King Stakh’s Wild Hunt, a guest performance the Bolshoi Theatre of Belarus on the Historic Stage of the Bolshoi Theatre of Russia.
In November 2022, he performed the role of Lensky at the Astana Opera, Kazakhstan, as part of the 4th Silk Road International Festival.
In April 2024, he appeared in the gala concert of the International Opera Festival “The Slavic House” at the Samara Academic Opera and Ballet Theatre.
In July 2024, as part of the company, he sang in the Gala Concert Marking the 80th Anniversary of the Liberation of Belarus from Nazi Invaders and the 45th Anniversary of the Nicaragua Revolution held at the Rubén Darío National Theatre in Managua, Nicaragua.
In October 2024, he performed the role of Svetsilovich in the company’s guest performance of King Stakh’s Wild Hunt at the Mariinsky Theatre given as part of the Days of the City of Minsk in St Petersburg.