[1] His talents were recognized at an early age by the sculptor Franz Anton von Zauner and by the time he was twelve, he was already attending the Academy of Fine Arts, Vienna.

[2] After the death of Alexei Sergeyevich Berezin [ru], a Russian nobleman who had been his patron there, he returned to Vienna and earned his living primarily as an illustrator and portrait painter, although he is also known to have painted shop signs.

With his brother, Joseph, he was a member of the "Schubertianer" (friends of Franz Schubert), a group that often got together for summers at the Schloss Atzenbrugg, west of Vienna.

In 1826, Leopold married Maria Johanna Evangelista Augustina Stephania Theodora Lutz, an occasion which was marked by Schubert's composition, the "Kupelwieser Waltz" (never written down, but passed along by the family and later transcribed by Richard Strauss).

Kupelwieser is honoured in street names in his birthplace (Kupelwieserstraße in Markt Piesting), Kupelwiesergasse in Hietzing, Vienna and in the Austrian towns of Wiener Neustadt, St. Pölten and Atzenbrugg.