Andrew Avellino(1521-1608) was an Italian Theatine priest. He is the patron saint of Naples and Sicily and invoked especially against sudden death. He was born in Castronuovo, Italy. His baptismal name was Lancelotto, later he changed to Andrew when he entered the Order of Theatines. He obtained the degree of Doctor in Laws and was ordained priest at the age of twenty-six. The archbishop of Naples commissioned him to reform a convent at Naples, which had become a source of great scandal by the laxity of its discipline.
Though indefatigable in preaching, hearing confessions, and visiting the sick, Avellino still had time to write some ascetical works. His letters were published in 1731 at Naples in two volumes, and his other ascetical works were published three years later in five volumes.
On 10 November 1608, when beginning the Holy Sacrifice of the Mass, he was stricken with apoplexy, and after receiving the Holy Viaticum, died at the age of 88. In 1624, only 16 years after his death, he was beatified by Pope Urban VIII, and in 1712 was canonized by Pope Clement XI. His remains lie buried in the Church of Sao Paolo Maggiore in Naples.