Grace Church dates back to colonial times, when it was located on Whitney Avenue and later Dixwell Avenue across the street from its present location. St. Peter's history is more recent, forming in 1958 after breaking away from St. Andrew's Episcopal Church in New Haven. The two parishes merged in 1990. At that time Grace Church's membership was dwindling with few younger members, while St. Peter's was growing. Grace Church had the endowment that St. Peter's lacked, so the two joined together to form Grace & St. Peter's Episcopal Church.
The church is very active in the community, collecting food for the Hamden Food Bank, leading worship services every Sunday at Arden House assisted living facility and helping out families at Church Street School during the holiday season.
Every Sunday Church School meets to educate young people on religious beliefs, and the church also runs a nursery school. Adult education programs also are available.