Thomas of Celano (Italian: Tommaso da Celano; c

Thomas of Celano (Italian: Tommaso da Celano; c. 1200 c. 1260-1270) was an Italian friar of the Franciscans (Order of Friars Minor), a poet, and the author of three hagiographies about Saint Francis of Assisi.

Thomas was from Celano in Abruzzo. The first of his works on Francis was Vita prima ("First Life"), a work on the saint's early life, commissioned by Pope Gregory XI in 1228 at the time Francis's canonization. The second work, Vita secunda ("Second Life") was commissioned by Crescentius of Jessi, the Minister General of the Franciscan Order sometime between 1244 and 1247, and reflects changing official perspectives on Francis in the decades after his death. The third is a treatise on the saint's miracles, written sometime between around 1254 and 1257 at the bidding of Blessed John of Parma, who succeeded Crescentius as Minister General.

Thomas's authorship of the three works on Francis of Assisi is well-established. Thomas also wrote Fregit victor virtualis and Sanctitatis nova signa in honor of Francis. Life of St. Clare of Assisi, on the early life of Saint Clare of Assisi and the hymn "Dies Irae" are also traditionally attributed to him, but the authorship of both works is in fact uncertain.

Thomas was not among the very earliest disciples of Francis, but he joined the Franciscans around 1215, during the saint's lifetime, and evidently knew him personally. In 1221, Thomas was sent to Germany with Caesarius of Speyer to promote the new order there, and in 1223 was named "sole guardian" (custos unicus) of the order's Rhineland province, which included convents at Cologne, Mainz, Worms, and Speyer. Within a few years he was back in Italy, where he seems to have remained for the rest of his life, with some possible short-term missions to Germany. In 1260 he settled down to his last post, as spiritual director to a convent of Clarisses in Tagliacozzo, where he died some time between 1260 and 1270. He was at first buried in the church of S.Giovanni Val dei Varri, attached to his monastery, but his body is now reburied in the church of S.Francesco at Tagliacozzo.