While a priest in the Roman Catholic Diocese of Albany for 17 years, Brian O'Shaughnessy served in numerous roles, including parish associate, HC chaplain and Director of the Peace and Justice Commission (which taught modules on “effective organizing for social justice” throughout the diocese). He also was the diocesan Refugee Resettlement Coordinator for 3 years. During this time, Brian lived in public housing in Troy in the tradition of 'worker priests' and served on local, state and national boards, including INFACT (which organized the Nestle Boycott), the Public Policy Committee of the NYS Catholic Conference, NY DIVEST, Troy Area United Ministries and the Capital District Community Loan Fund.
In 1989 Brian left the ordained ministry, married and became Executive Director of the New York State Labor-Religion Coalition – until semi-retirement in 2011. Coalition priorities were justice for low-wage workers, international labor solidarity and Fair Trade. As Advocacy Consultant for RMM, his responsibilities include fundraising, advocacy and consulting with the Executive Director.