[2] Quinn had a classical and general education in Ireland before undertaking theological studies at the Irish College, Rome.

When a prominent Orangeman Rev Porteus gave a speech in Ipswich that angered the Irish Catholics, a riot was feared at a picnic to be held by the Orangemen the following day.

Quinn travelled to Ipswich and used his influence with Catholics to calm them and then he attended the picnic to spread goodwill among the Protestants.

[9] He died in his home Dara in Fortitude Valley on 18 August 1881 aged 62,[5] having done a good deal to moderate the acerbity of Irish factional feeling during his episcopate.

The procession was led by the clergy, followed by the coffin and its pallbearers, the Sisters of Mercy, the children from Catholic schools, and then the public.

O'Quinn's body was robed and lay in state in front of the high altar, where hundreds of people came to the church to pay their respects.

When the procession returned to St Stephen's, O'Quinn's coffin was lowered into the vault prepared by architect Andrea Stombuco and covered with a marble slab.