Joel Siepmann was born in Tübingen, Germany, where he started playing the cello at the age of 6. From 2011 until 2015 he studied at the Folkwang University of Arts in Essen with professor Christoph Richter and completed his Bachelor degree with distinction.

In 2016 he started his Masters degree at the Royal Academy of Music with Guy Johnston as his teacher generously supported by the German Academic Exchange Service (DAAD). He completed the degree in 2018 with distinction and was awarded the Queens award for Excellence for best all-round studentship. 

With his piano trio Trio Opal he has won several prizes at the 2019 Trondheim International Piano Trio Competition.  Through his career he has performed with various orchestras and ensembles in the great concert halls of London, Berlin, Paris, St. Petersburg, Amsterdam, Seoul, Tokyo and Shanghai.

Further coachings and lessons with Lynn Harrell, Anner Bylsma, Jerome Pernoo, Colin Carr, Misha Maisky and Steven Isserlis were very important for his musical development.

Since April 2020 he is principal cellist of the world famous Metropole Orkest and member of the cello quartet Metrocelli which released their self-titled debut in 2021.

He plays on a cello by Ludovic Guersan (Paris 1760).