Born in Amsterdam, Sebastiaan van Halsema began playing the cello at the age of six with Denise Rosing at the Municipal Music School of Zaanstad. At twelve, he was admitted to the Young Talent Class of the Amsterdam Conservatory, where he studied for six years with Maarten Mostert. He continued his studies at the Guildhall School of Music & Drama in London with Louise Hopkins. In 2008, he graduated from Guildhall as cum laude with his Bachelor’s degree and was awarded the prestigious Concert Recital Diploma. He subsequently completed his Master’s degree at the same institution in 2010.
Van Halsema has appeared as a soloist with many orchestra's, including the Netherlands Promenade Orchestra, the Netherlands Youth String Orchestra and the North Holland Youth Orchestra and Caecilia Camerata. Since 2012, Sebastiaan has served as Associate Principal Cellist with Phion and has been a member of the Het Muziek since 2018. In addition, he is an active chamber musician, performing regularly in a wide variety of settings throughout the Netherlands and internationally.