There has been a church on this site since at least 1230. That much is known for certain since Primate Donal O'Fidabra is recorded as holding a Synod there in that year. Many suspect that there was a church here in early Celtic times, Lost in the mists of time as the early days may be, to know for sure that this was Holy Ground three hundred years before the Reformation is history enough.

In 1649, during the siege of Drogheda, Cromwell destroyed the church, firing the steeple to kill or capture one hundred people who had taken refuge there. Soon afterwards, perhaps out of remorse for their actions, Cromwell's army subscribed a considerable sum to repair St. Peter's church.

It seems this wasn't enough. According to the Vestry Minute Books, in "the Year one thousand seven hundred and Forty Seven, The Old Parish Church of Saint Peters Drogheda being in a ruinous condition and in danger of falling was Order'd to be pulled down which was done accordingly and a new Church begun to be built in the room of the old one the same year". The present church was started in 1747 and is shown on Ravell's map of Drogheda of 1749.

To be illustrated on one of Joseph Ravell's famous maps in the mid 1700s was a great distinction for any building, sacred or secular. Of the ten that framed this map of Drogheda, only two still stand: St. Peter's and Barlow House.