| Office: | Lord Mayor of Dublin |
| Term Start: | 4 July 1886 |
| Term End: | 15 July 1888 |
| Predecessor: | John O'Connor |
| Successor: | Thomas Sexton |
| Office1: | MP for West Donegal |
| Term Start1: | 7 July 1892 |
| Term End1: | 25 October 1900 |
| Predecessor1: | James Joseph Dalton |
| Successor1: | James Boyle |
| Office2: | MP for Dublin College Green |
| Term Start2: | 1 December 1885 |
| Term End2: | 5 July 1892 |
| Predecessor2: | New office |
| Successor2: | Joseph Edward Kenny |
| Office3: | MP for Westmeath |
| Term Start3: | 1 April 1880 |
| Term End3: | 25 November 1885 |
| Predecessor3: | Patrick James Smyth Lord Robert Montagu |
| Successor3: | Office abolished |
| Birth Name: | Timothy Daniel Sullivan |
| Birth Date: | 29 May 1827 |
| Birth Place: | Bantry, County Cork, Ireland |
| Death Place: | Dublin, Ireland |
| Nationality: | Irish |
| Party: | Irish Parliamentary Party |
| Spouse: | Catherine (Kate) Healy |
| Children: | 3 |
| Alma Mater: | Trinity College Dublin |
Timothy Daniel Sullivan (29 May 1827 – 31 March 1914) was an Irish nationalist, journalist, politician and poet who wrote the Irish national hymn "God Save Ireland", in 1867. He served as Lord Mayor of Dublin from 1886 to 1888 and a Member of Parliament (MP) from 1880 to 1900.
Sullivan was a member of the Home Rule League, supporting Charles Stewart Parnell in the 1880 general election, being "convinced that without self-government there could never be peace, prosperity or contentment in Ireland". He joined the Irish Parliamentary Party when it was established in 1882. When the party split in 1891, he became an Anti-Parnellite until the Nationalist factions were reunited in 1900.
Sullivan represented a number of constituencies in the House of Commons of the United Kingdom of Great Britain and Ireland. He was elected as an MP for Westmeath in 1880 and served until 1885. In 1885, he was elected to the newly created constituency of Dublin College Green. He joined the anti-Parnellite Irish National Federation in 1891, and was defeated by a Parnellite in the 1892 general election. Four days later he was returned unopposed for West Donegal which he represented until he retired in 1900.
He was Lord Mayor of Dublin in 1886 and 1887.[1]
He owned and edited a number of publications (The Nation, Dublin Weekly News and Young Ireland). In December 1887, he published reports of meetings by the Irish National League. As a result, he was convicted and imprisoned for two months under the Crimes Act.
As well as writing the Irish national hymn "God Save Ireland", he wrote the adopted anthem of the All-for-Ireland League: "All for Ireland! One for all! and popular pieces such as Dear Old Ireland, "Song from the Backwoods" and "Michael Dwyer".[2]
He was married to Catherine (Kate) Healy who was the sister of Tim Healy, the first Governor General of the Irish Free State in 1922. A number of his descendants were people of outstanding distinction. His son Timothy was Chief Justice of Ireland from 1936 to 1946. His daughter Frances was an Irish-language activist in Irish: Craobh an Chéitinnigh, the Keating branch of the Gaelic League (Conradh na Gaeilge) and a lecturer in Irish. His daughter Anne (who had sixteen children) was the mother of politician Kevin O'Higgins, one of the dominant political figures of the 1920s. Sullivan's great-grandson Tom O'Higgins served as Chief Justice of Ireland from 1974 to 1985.[3]
His brother, Alexander Martin Sullivan, author of New Ireland and a fervent constitutional and cultural nationalist, was the owner and editor of The Nation after Gavan Duffy, and prior to Timothy Daniel Sullivan.[4]