The Franz Lehár-Orchestra was founded by Eduard Macku as the “Viennese Concert Orchestra” in 1945. After a successful concert tour of the United States the Lehár family bestowed the title of "Franz Lehár-Orchestra" on the orchestra.
In 1961 Eduard Macku founded the Bad Ischl Operetta Festival - today the Bad Ischl Lehár Festival - and made the Franz Lehár-Orchestra a permanent fixture of the festival.
After the death of Eduard Macku Gabriel Patocs assumed conducting duties of the orchestra in Vienna, while Walter Erla was appointed conductor of the orchestra in Bad Ischl.
During the festival directorship of Martin C. Turba (2000 - 2003) and Michael Lakner (2004 - 2016) and Thomas Enzinger (2017 up to present) the Franz Lehár-Orchestra performed under such notable conductors as Franz Bauer-Theussl, Herbert Mogg, Alfred Eschwé, Wolfgang Bozic, Marius Burkert, Vinzenz Praxmarer, and Oliver Ostermann.
At the turn of the year 2011-12 the Chinese Cultural Society in Austria engaged the orchestra for a highly successful concert tour of China. This was followed by the participation of the orchestra in the 2012 Chinese New Year’s concert as well as the European debut of the Chinese soprano Ma Yiming. Both concerts took place in the Golden Hall of the Vienna Musikverein. Further activities are in planning with the Chinese Cultural Society in Austria.
In 2012 the orchestra attracted the attention of the well-known Viennese entertainer Herbert Prikopa who engaged it for the newly created Oscar Straus Voice Competition in Vienna.
In addition to its concert activity the Franz Lehár-Orchestra has been a regular element of the Viennese ball scene – in the Vienna Hofburg among others – since the 1970s.