He was born in Castello Cagliaglio (Varese) on the 11th of February 1715, the son of Giacomo who was a shopkeeper. Educated in humanistic studies in L'Aquila he was in Rome between 1734 and 1740, the pupil of Francesco Mancini.
He worked in various towns/cities in Piedmont and Lombardy.
In the area of Varese his frescoes are conserved in Palazzo Estense (formerly the residence of Francesco III, a Villa Recalcati, in Casa Bossi in Azzate and in Villa Della Porta Bozzolo in Casalzuigno.
Ronchelli died in Cabiaglio on the 14th of January 1788.