Johann Baptist Klerr (15 July 1830 – 27 September 1875) was an Austrian Kapellmeister and composer.
In 1848 Klerr got an engagement as a musician at the Schauspielhaus Graz [de] and from there he later went to the city theatre in Bratislava in the same function.
The next stages were Wiener Neustadt, Baden and after a short guest performance in 1858 in Kraków, Klerr was signed on in Budapest.
In 1862 he was engaged as Kapellmeister at the Carltheater in Vienna and worked there until 1867 among others also with Franz von Suppé.
Klerr died at the age of 45 in Baden, where he also found his final resting place.