A common theme throughout St. Andrew’s history is the cooperation between different Christian denominations. The church traces its history back to Catholic Irish immigrants in Oakville, who traveled to Dundas in 1819 to ask Father O’Reilly to come back with them to say Mass in their log cabin. Twenty years later an Oakville mission had been established and land for a church on the corner of King and Reynolds had been donated by town founder and Scottish Presbyterian William Chisholm. As thanks for this donation, the church was named after the patron saint of Scotland, and when the Methodists needed funds to build a church in the 1850s, parishioners made contributions to their fund. St. Andrew’s was finished in 1840, and the first mass in the new church was said that same year. For the first few years, priests would only visit once every five weeks to say mass, having to make a two day trip from Dundas. In 1859, St. Andrew's finally had a resident pastor, Reverend Jeremiah Ryan, which allowed Oakville residents to attend mass more often without travelling all the way to Dundas. Reverend Jeremiah Ryan remained at St. Andrew's for seventeen years.
Annual garden parties started being held at the church in 1896, where community bands and local celebrities would make appearances.
Much more recently, there were Sesquicentennial celebrations in 1990, and various church and community events were held for the Jubilee celebrations in honour of the 2000th anniversary of Christ’s birth. Each year from 1997 to 2000 focused on a different theme: Jesus, The Holy Spirit, The Father, and The Sacrament of the Eucharist.
St. Andrew’s began as a parish of poor, hardworking pioneers who were ministered to by mission priests, so it was fitting they marked their 175th anniversary in 2015 with a ”Faith in Action” fundraising campaign for mission priests in Newfoundland and Labrador. For two centuries, St. Andrew’s parishioners have helped their neighbours build their own homes and places of worship. In 2016, the parish welcomed two families of Syrian refugees. On an ongoing basis many parish groups including the Society of St. Vincent de Paul are dedicated to providing practical help to the poor in the community.
