Michael O'Connor, born in Dublin, began his professional life as a heraldic artist, but along with many other early 19th-century practitioners of that art he decided to move into the renascent field of stained-glass design.
[3][4] Going to London in 1823, he studied this art under Thomas Willement, one of the leaders of the revival of stained-glass manufacture in Britain, and then returned to Dublin to establish his own business.
[5][4] In an 1839 trade directory he is listed as a "professor of heraldry, stained glass enameller, and ornamental painter, print & bookseller, and fancy stationer".
[6] He moved his business to Bristol in 1842,[1] and there began to work with Augustus Pugin, under whose influence he adopted a neo-medieval style[7][8] later to be praised by Pevsner for its avoidance of "Victorian dimness and fussiness of small detail".
[19] In 1856 O'Connor developed problems with his eyesight[20] which increasingly necessitated his assigning work to his sons Arthur and William Henry.