Spanish naturalist and man of letters known for his campaign against public performance of the Corpus Christi autos sacramentales, one-act, open-air dramas that portrayed the eucharistic mystery. From his position as editor of the literary periodical El pensador, he issued constant attacks against the performance of these plays, which had become little more than vulgar public spectacles. Because of his activity, the autos sacramentales were eventually banned in 1765. His love affair with Louise, sister of the French playwright Pierre-Augustin Caron de Beaumarchais, was dramatized by the German dramatist Johann Wolfgang von Goethe in his tragedy Clavigo.

Largely educated in France, Clavijo was responsible for translations of Racine and Voltaire and translated the French naturalist Buffon's Histoire naturelle (1791–1802; “Natural History”). Besides his literary activity, he was also vice director of the Museum of Natural History, Madrid.