In his early years, Ondřej Holub was a member of the Kühn Children’s Choir and the Pueri Gaudentes Boys Choir. He studied classical singing privately with prof. Lenka Pištěcká, then he continued at the Prague Conservatory – prof. Valentin Prolat, and, at the present time, he studies with prof. Jiří Kotouč. Since 2017 he has been cooperating with the Ensemble Damian – artistic leader Tomáš Hanzlík – which focuses on rediscovering of baroque operas. He has performed in the operas La contesa de numi by Leonardo Vinci (part of Marte) and L’Amor non há legge by Antonio Caldara (Tirsi). Both of these operas were presented at the Olomouc Baroque Festival, and L´Amor non há legge was performed three more times at Smetanova Litomyšl festival 2018 in castle Nové Hrady. As a soloist, he cooperates with numerous ensembles and orchestras (South Bohemian Philharmonic Orchestra, Hradec Králové Philharmonic Orchestra, Canticorum Iubilo, etc.). At present, he is a member of top Czech ensembles focused on early music – Collegium 1704, Schola Gregoriana Pragensis, Cappella Mariana, Collegium Marianum, Ensemble Inégal, Musica Florea, The Czech Baroque Ensemble, Victoria Ensemble. During 2013-2019 period, he was a member of Martinů Voices vocal ensemble, whose main field of activity is the music of 20th century and contemporary music as well. He participates regularly in prestigious domestic and foreign festivals. In 2007, he became a member of the male vocal quintet Rudolfvoice founded by former members of Pueri Gaudentes Boys Choir, and he sung with this quintet at the Kennedy Center in Washington. In addition, he cooperates externally with the Prague Philharmonic Choir, and participated in the performance of Mahler’s 2nd Symphony in Carnegie Hall in New York given at the occasion of the 100th anniversary of the foundation of Czechoslovakia.