 A church building had existed on the site since <unk> . During this time , a small chapel stood on the site to serve the local townships of Oldham , Chadderton , Royton and Crompton . This was later replaced by an Early English Gothic church in the 15th century . With the coming of the Industrial Revolution , the population of Oldham increased at a rapid rate ( from under 2 @,@ 000 in 1714 , to over 32 @,@ 000 by 1831 ) . The rapid growth of the local population warranted that the building be rebuilt into the current structure . Though the budget was originally agreed at £ 5 @,@ 000 , the final cost of building was £ 30 @,@ 000 , one third of which was spent on the crypt structure . Alternative designs by Sir Charles Barry , the designer of the Palace of Westminster , although now regarded by some as superior , were rejected . The Church , of the Anglican denomination , is in active use for worship , and forms part of the Diocese of Manchester . There are Roman Catholic churches in Oldham . These include Our Lady of Mount Carmel and St Patrick Church . It was built in 1870 , was founded by priests from St Mary 's Church in Oldham , and is a Grade II listed building . 
