String Trio No.1, Op.34

Joseph von Blumenthal, also known as Joseph de Blumenthal (1 November 1782 – 9 May 1850), was an Austrian violinist and violist, influential pedagogue and composer.

Joseph von Blumenthal was born in Brussels, the son of Baron Joseph von Blumenthal and Baroness Maria Therese, née Malabreck. His father, who had a job with the Austrian government, took the family to Prague during the Brabant Revolution (1789–1790). The young Blumenthal and his two brothers, Casimir and Léopold, learned to play the violin and studied composition with Abbé Vogler. When Vogler went to Vienna in 1803 to produce his opera Samori, he recommended his students to the director of the Theater an der Wien, and on his testimony, they were accepted into the theatre orchestra, Joseph on viola, his siblings on violin. From 1842 to 1844 Blumenthal was choirmaster at the Piarist Church, Vienna.

During the first two decades of the nineteenth century, Joseph von Blumenthal wrote a great deal of dramatic music, of which a part was attributed to his brothers. He composed music for the stage including an opera and ballet, symphonies, some chamber music and vocal works. Blumenthal also wrote a considerable amount of music for violin: many concert pieces and instructive works, including a Violin Method (published Vienna, 1805) and a treatise on harmonics (published Vienna, 1829).

His brother Casimir von Blumenthal (1787–1849) went on to become music director in Zurich, and Léopold von Blumenthal (born 1790) was a musician employed by a nobleman in Hungary. Both published compositions for violin and various other works.