Joseph Patrick Nannetti (1851 – 26 April 1915), was an Irish nationalist Home rule politician, trade union leader, and as Irish Parliamentary Party member and Member of Parliament (MP) represented the constituency of College Green, Dublin in the House of Commons of the United Kingdom of Great Britain and Ireland 1900–1915. He was a city councillor and Lord Mayor of Dublin.
Nannetti was born in 1851 as son of an Italian sculptor and modeller. He was educated at the Baggot Street Convent School and the Christian Brother’s schools in Dublin. He married Mary, daughter of Edward Egan, in 1871.
First apprenticed to the printing trade and was afterwards employed in Liverpool, where he was one of the first founders of the Liverpool Home Rule organisation in Liverpool. Returning home, he became secretary of the Dublin Trade Council, afterwards its President; he also led the Dublin Typographical Provident Society.
In the 1900 general election Nannetti was elected MP for the constituency of College Green, Dublin as a United Irish League supported Labour trade unionist, as well as in the 1906 election, the January 1910 and the December 1910 elections which seat he held until his death in 1915, having been paralysed by illness since 1913.