Daniel Florence O'Leary (Irish: Dónall Fínín Ó Laoghaire; 1801–1854) was a military general and aide-de-camp under Simón Bolívar.
He was born in Cork, Ireland; his father was Jeremiah O'Leary, a butter merchant. In 1817, he emigrated to South America.
Unlike many of the Irish who fought for Simon Bolívar in his many campaigns to win South American independence, O'Leary had not served in the Napoleonic Wars.
In 1827 he married Soledad Soublette, the younger sister of General Carlos Soublette, with whom he had nine children.
After Bolívar's death in 1830, O'Leary disobeyed orders to burn the general's personal documents. He spent much of the rest of his life organizing them, along with writing his own very extensive memoirs (spanning thirty-four volumes) of his time fighting in the revolutionary wars with Bolívar. He died in Bogotá, Colombia. He is buried in the National Pantheon of Venezuela.
A bust and plaque honouring O'Leary were presented by the Venezuelan Government to the people of Cork and unveiled on 12 May 2010 by the Venezuelan Ambassador to Ireland, Dr. Samuel Moncada.