Franz Sigrist came from his native town to Vienna at he age of 17. In 1744 he matriculated at the Viennese Academy, and in 1752 he won the second prize in the academic competition. At this time he already worked as an autonomous Historienmaler. In 1754 he moved to Augsburg, became a professor of Augsburg's Academy of fine Arts and took an active part in the artistic life of the city. He painted frescoes (Augsburg, Zwiefalten 1760) and altarpieces as well as small devotional pictures and biblical scenes for various Augsbrug publications.

In the 1760s he returned to Vienna. He took part in the monumental artistic enterprise which, commissioned by the imperial house, was organized by Martin van Meytens for the painting of various historical and courtly events. Between 1772 and 1775 he painted the ceiling fresco of Liechtental (Vienna) parish church.

In 1780 he executed one of the most significant works of his life, the hall of the Lyceum of Eger. The Bishop of Eger Károly Eszterházy who, after the death of his painter in Johann Lucas Kracker, was urgently looking for a painter in Vienna to realize his plan for the decoration of the monumental new building of Eger Lyceum (universitas), established relations with Sigrist via the intermediation of the imperial court astronomer Miksa Hell. On the basis of the programme devised by the bishop and the preparatory sketches. Sigrist worked three years on the hall's ceiling fresco. The painting representing the four university faculties, in contrast to the earlier, allegorical representations of the same theme, shows real activities and contemporary figures. Its well-arranged and rational pictorial approach matches the new Neo-Classic view of the end of the century.

After his successful work in Eger, Sigrist executed only modest commissions (Ruszt [Rust] parish church), amongst them little panel and genre paintings.