Costantino Cristiano Luna Pianegonda (10 December 1910, Recoaro Terme, Italy - 29 August 1997, Zacapa) was an Italian Franciscan friar and clergyman.
He was ordained priest by the Franciscans on 1 July 1934 before being appointed first bishop of Zacapa in the Archdiocese of Guatemala on 30 November 1955.
He was enthroned on 6 January 1956 by archbishop Gennaro Verolino, then apostolic nuncio in Guatemala.
He resigned on 16 February 1980 and remained a bishop emeritus of the diocese until his death.
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