A native of Pietracatella, Italy, d'Elia entered the Society of Jesus in 1904. He studied philosophy on the Island of Jersey and was in Zikawei (Xujiahui), near Shanghai, China, from 1913 to 1917, after which he completed his theological education at Woodstock, Maryland, and Hastings, England. Returning to China in 1923, he was a professor of English and philosophy at Aurora University in Shanghai until 1930. He later was a researcher and writer at the Jesuit center at Zikawei. He became a professor at the Gregorian University in Rome in 1933, where he instituted a chair of missiology. He is best known for his publications about Matteo Ricci.