Ernst Gottlieb Baron or Ernst Theofil Baron (17 February 1696 – 12 April 1760), was a German lutenist, composer and writer on music.

Baron was born in Breslau into the family of Michael Baron, a maker of gold lace who expected his son to follow in his footsteps. Baron showed an inclination to music from an early age, and later made it his profession. He studied lute from about 1710 with a Bohemian named Kohott. He attended the Elisabeth Gymnasium in Breslau, and from 1715 the University of Leipzig, where he studied philosophy and law.

He spent the period from 1719 to 1728 in travels from one small court to another. He visited Halle, Köthen, Schleiz, Saalfeld and Rudolstadt, arriving in Jena in 1720 and remaining for two years. Later he travelled to Kassel, Fulda, Würzburg, Nuremberg and Regensburg, returning in 1727 to Nuremberg where he published his "Historisch-theoretische und practische Untersuchung des Instruments der Lauten", the work for which he is principally remembered. In 1728 he replaced the lutenist Meusel, who had recently died in a horseback riding accident, at the court of Gotha. He held that post for four years. After the death of the Duke of Gotha he moved on to Eisenach.

In 1737 he visited Merseburg, Köthen and Zerbst, and eventually joined the musical ensemble of Crown Prince Frederick of Prussia as a theorbist. He was immediately granted permission to go to Dresden to purchase a theorbo. In Dresden he received tuition from the lutenists Sylvius Leopold Weiss and I.A. Hofer.

After Frederick's accession in 1740, Baron continued to serve as theorbist in the royal musical establishment, and remained at this post until his death in Berlin.