Established following the founding of George Town in 1786, it is the third oldest Catholic church in Malaysia.

The pipe organ, by Morton & Moody of Oakham, England, was installed in 1916 and the choir gallery was extended.

In 1954, in conjunction with the Marian Year, the statue of Our Lady of Fatima was carried on a long procession through the streets of George Town.

After much discussion, finally on 25 February 1955, the Penang Diocese was established together with the Archdiocese of Kuala Lumpur.

At that period of time, Cathedral of the Assumption served as the main church of the northern region of Malaysia.

That was also the time when the Bishop of Penang had a meeting with the priests to discuss about moving the cathedral to some other places.

A concert was held in June 2014, and various choirs were invited to sing and celebrate the restoration of "The Old Lady" organ.

[6] In August 2016, the church was closed for 16 months to undergo a RM 2.5 million restoration project which included landscaping, repainting of the building, reconstruction of the sanctuary and installation of air conditioning units.

The organ is usually played for Saturday sunset masses and also during festivities like Easter and Christmas.

Every year, on 15 August, the feast day of this church, the Assumption of the Blessed Virgin Mary is celebrated.