With the outbreak of the Troubles in Northern Ireland in the late 1960s, Ó Conaill would become a prominent spokesperson for the Provisional IRA. He was active in the IRA through the 1960s, and IRA Chief of Staff Cathal Goulding appointed him the Officer Commanding (O/C) of the Donegal unit prior to the IRA's Convention in December 1969; Ó Conaill was also a member of the IRA's Army Council after Goulding expanded that body at the IRA Convention late in 1968. In the autumn of 1969, Ó Conaill, upset with the then IRA leadership, walked out of the "unit convention" and was suspended.