Giovan Battista Dell'Era was the son of a brazier, but his predilection for art induced him to go to Bergamo and become a pupil of Francesco Dagiù, called Capella. The painter completed his training at the Brera Academy, studying with Giuliano Traballesi, Giocondo Albertolli and Giuseppe Franchi. In 1783 Count Peter de Salis, governor of Valtellina, hired Dell'Era as a drawing teacher for his children. In 1785 the count financed the painter's first Roman stay, which was then extended for the following two years, and Dell’Era chose Rome as the main seat of his activity, initially establishing himself as a portrait painter.
In Rome, the Bergamo cardinal Francesco Carrara introduced the artist into Angelika Kauffman's circle, thus entering into acquaintance with her husband Antonio Zucchi, with Volpato and Tischbein, but above all with Johann Friedrich Reiffenstein, artistic agent of Catherine II, which in 1786 involved the painter in the creation of encaustic copies of Raphael's Vatican Loggias to be placed in the Hermitage.
From 1789 to 1791 the artist was a pensioner in Rome at the Brera Academy, spending the last year on a stay in Florence intended to copy the masterpieces of Andrea del Sarto, Rubens and Gherardo delle Notti preserved in the Uffizi. Confirmed as a retired student of the Italian Academy for the four-year period 1791-1795, the painter began to frequent Felice Giani's Accademia de' Pensieri, from where he drew that taste for a non-conformist language sensitive to the visionary classicism introduced in Rome by Nordic artists. Appointed member of the Clementine Academy in 1797, the following year Dell'Era abandoned Rome, devastated by the revolutionary riots, to flee to Florence, where he died.