The Most Reverend Robert McGuckin's ordination comes after a tumultuous year for the church in the state's south.
Bishop McGuckin has held leadership positions in the archdiocese of Sydney and diocese of Parramatta.
He is now in charge of an area that stretches from the Lockyer Valley to the South Australian border.
For 18 years it was presided over by Bishop William Morris.
The Vatican forced him to retire last year after he suggested the church consider ordaining women and married men to arrest a decline in the number of priests.
The Vatican's decision prompted a backlash from parishioners and an investigation by a QC found Bishop Morris was denied natural justice.