Born in San Rocco al Porto in 1867, Mezzadri was ordained a Catholic priest on 11 August 1889; he was a priest in three parishes of the Diocese of Lodi. He was appointed bishop of Chioggia on 2 July 1920 and ordained Bishop on 22 August 1920.[1]
During his ministry as bishop he celebrated the first diocesan Eucharistic Congress, in 1923, and two pastoral visits, in 1922 and 1930, respectively. In 1927 he reopened the church of San Michele Brondolo for worship and in 1935 he consecrated the little church of the Capuchins in the cemetery of Chioggia.
He instituted a diocesan council of the Catholic movement.
He governed the diocese until his death on 8 December 1936 and was buried in the diocesan cathedral with his predecessors.[2]