Stefan de Leval Jezierski is an American horn player and currently the longest serving hornist of the Berlin Philharmonic Orchestra.

For Stefan, there were two good reasons to change from the trumpet to the horn: he was infatuated with the way the larger instrument sounded and looked. Moreover, the wind orchestra of his school needed a horn player; his favorite composer, Mozart, wrote more for the horn than for the trumpet; and, not least, the professional prospects with this instrument seemed better. The native Bostonian was trained at the North Carolina School of Arts and by Myron Bloom at the Cleveland Institute of Music. During his studies he was already performing in concerts and on tours with the Cleveland Orchestra. Before he took the high horn position with the Berliner Philharmoniker in 1978, he had spent two years as principal horn of the Kassel Staatstheater. As a soloist and chamber musician, Stefan de Leval Jezierski appears at leading international music festivals in Europe, Asia and North America. He is one of the founding members of the Scharoun Ensemble of Berlin. In addition, he has taught for a number of years in the Orchestra Academy of the Berliner Philharmoniker and as honorary professor at the Shanghai Conservatory. Jezierski has a jazz band, has played for over 20 years on the tennis team of the Grunewald Tennis Club, and is also greatly interested in art.