In 1872, the town of Westville became a mission of New Haven's St. John the Evangelist Church.  Father Hugh Carmody of St. John celebrated the first Mass in Westville at Franklin Hall on Fountain Street.  Shortly thereafter, an Emerson Street mission chapel, named for St. Joseph, was erected.  It was later dedicated by Bishop Francis P. McFarland.  In 1895 Westville became a mission of St. Lawrence parish, West Haven. 

 

Numbering about 375 communicants, the Westville mission was made a parish dedicated to St. Joseph on June 10, 1900, with Father John D. Kennedy appointed first pastor.  Father John McGivney, brother of Father Michael McGivney, bought land at Fountain Street and McKinley Avenue for a new church.  Bishop John J. Nilan dedicated the sturdy new building to St. Aedan on April 2, 1922.  The parish patron had been changed because Westville had become part of New Haven, which already had a church named for St. Joseph. 

 

By October 1950, St. Aedan built and opened an elementary school on McKinley Avenue, staffed by the Sisters of Notre Dame de Namur.  On October 26, 1957, a bigger school and new convent were dedicated by Archbishop Henry J. O'Brien. 

 

In 1990 Father McCann initiated significant upgrades to the church to align with the teachings of the Second Vatican Council. 

 

St. Aedan Parish became Saints Aedan and Brendan Parish in 2016 when St. Aedan Church and St. Brendan Church merged, and the property and buildings of St. Brendan were sold in 2017. Many items from St. Brendan Church were transferred to Sts. Aedan and Brendan Parish on Fountain Street. The original art sample of the crucifix which hanged above St. Brendan's sanctuary hangs above the tabernacle.  The statue of the Sacred Heart is located at the McKinley Avenue side entrance and the St. Brendan statue was installed in the rear of the Church.