[2] With a background in community development projects, in 2002 he was co-opted into the council to replace his Green Party colleague Dan Boyle who had been elected a TD.

[3] O'Leary left the Green Party in 2009,[4] and was an independent councillor prior to joining Sinn Féin in 2010.

[5] He became Lord Mayor of Cork in June 2015,[6] in the second year of a D'Hondt method rotation agreed for the office in 2014.

[10] In the 2019 Irish local elections, O'Leary was not reelected, one of two Sinn Féin councillors to lose seats on Cork City Council.

[11] His brother Don O'Leary was also a Sinn Féin Councillor for Cork City.