Aloysia Weber was born in Zell im Wiesental, in the Black Forest region of Germany, on November 12, 1760. Her father, Fridolin Weber, was a musician and music teacher, and her mother, Cäcilia Weber, was a singer. Aloysia showed early talent in music, and she began studying piano and voice with her father.
In 1777, Aloysia and her family moved to Munich, where she made her stage debut at the age of 17. She quickly became a successful opera singer, performing in leading roles in operas by Mozart, Gluck, and other composers.
In 1780, Aloysia met Wolfgang Amadeus Mozart, who was then living in Munich. Mozart was immediately smitten with Aloysia, and he composed several arias for her. The two were engaged to be married, but the engagement was broken off in 1781.
Aloysia continued to perform successfully as an opera singer until 1790, when she retired from the stage. She married Joseph Lange, a court musician, in 1795. The couple had two children, a son and a daughter.
After her retirement, Aloysia Weber devoted herself to teaching music. She taught piano and voice to students of all ages, and she was a respected music teacher in Vienna for many years. She died in Vienna in 1839.