Cosgrave, who was leader of the Republic’s government during some of the most turbulent years of the Northern Ireland conflict, has been described as a courageous voice against terrorism.
In his public life, the late statesman was a figure of great integrity and a true patriot, Monsignor John Wilson told mourners.
He said: “Liam left our country a better place as a result of his life and his life’s work.”
Cosgrave died on Wednesday aged 97.
His son, also Liam, said: “Affection, kindness, love and loyalty dad gave to us in abundance.”
The Republic’s current premier Leo Varadkar, and his predecessors Enda Kenny and Bertie Ahern, were among those who attended the simple service at the Church of the Annunciation in Rathfarnham in south Dublin yesterday.
Ten military policemen had carried his remains into the church in the middle-class surroundings near where he built his political power base as part of a dynasty stretching back to the state’s foundation.
Born in 1920, the Dubliner had a 40-year political career and was part of the government which saw Ireland become a Republic in 1949.
He also oversaw Ireland joining the United Nations, addressed the US Congress in 1976 and signed the Sunningdale Agreement in Northern Ireland which led to a short-lived power-sharing executive in Belfast in 1972.