Taoiseach: Gwahaniaeth rhwng fersiynau

<tr bgcolor=#DDFFDD><td>1.<td>[[Éamon de Valera]] <td> [[Fianna Fáil]] <td> [[29 Rhagfyr]] [[1937]] <td> [[18 Chwefror]] [[1948]]

<tr bgcolor=#DDEEFF><td>2.<td>[[John A. Costello]] <td> [[Fine Gael]] <td> [[18 Chwefror]] [[1948]] <td> [[13 Mehefin]] [[1951]]

<tr bgcolor=#DDFFDD><td><td>[[Éamon de Valera]] (''am yr ail dro'') <td> [[Fianna Fáil]] <td> [[13 Mehefin]] [[1951]] <td> [[2 Mehefin]] [[1954]]

<tr bgcolor=#DDEEFF><td><td>[[John A. Costello]] (''am yr ail dro'') <td> [[Fine Gael]] <td> [[2 Mehefin]] [[1954]] <td> [[20 Mawrth]] [[1957]]

<tr bgcolor=#DDFFDD><td><td>[[Éamon de Valera]] (''am y trydydd tro'') <td> [[Fianna Fáil]] <td> [[10 Mawrth]] [[1957]] <td> [[23 Mehefin]] [[1959]]

<tr bgcolor=#DDFFDD><td>3.<td>[[Sean Lemass]] <td> [[Fianna Fáil]] <td> [[23 Mehefin]] [[1959]] <td> [[10 Tachwedd]] [[1966]]

<tr bgcolor=#DDFFDD><td>4.<td>[[Jack Lynch]] <td> [[Fianna Fáil]] <td> [[10 Tachwedd]] [[1966]] <td> [[14 Mawrth]] [[1973]]

<tr bgcolor=#DDEEFF><td>5.<td>[[Liam Cosgrave]] <td> [[Fine Gael]] <td> [[14 Mawrth]] [[1973]] <td> [[5 Gorffennaf]] [[1977]]

<tr bgcolor=#DDFFDD><td><td>[[Jack Lynch]] (''am yr ail dro'') <td> [[Fianna Fáil]] <td> [[5 Gorffennaf]] [[1977]] <td> [[11 Rhagfyr]] [[1979]]

<tr bgcolor=#DDFFDD><td>6.<td>[[Charles J. Haughey]] <td> [[Fianna Fáil]] <td> [[11 Rhagfyr]] [[1979]] <td> [[30 Mehefin]] [[1981]]

<tr bgcolor=#DDEEFF><td>7.<td>[[Garret FitzGerald]] <td> [[Fine Gael]] <td> [[30 Mehefin]] [[1981]] <td> [[9 Mawrth]] [[1982]]

<tr bgcolor=#DDFFDD><td><td>[[Charles Haughey]] (''am yr ail dro'') <td> [[Fianna Fáil]] <td> [[9 Mawrth]] [[1982]] <td> [[14 Rhagfyr]] [[1982]]

<tr bgcolor=#DDEEFF><td><td>[[Garret FitzGerald]] (''am yr ail dro'') <td> [[Fine Gael]] <td> [[14 Rhagfyr]] [[1982]] <td> [[10 Mawrth]] [[1987]]

<tr bgcolor=#DDFFDD><td><td>[[Charles Haughey]] (''am y trydydd tro'') <td> [[Fianna Fáil]] <td> [[10 Mawrth]] [[1987]] <td> [[11 Chwefror]] [[1992]]

<tr bgcolor=#DDFFDD><td>8.<td>[[Albert Reynolds]] <td> [[Fianna Fáil]] <td> [[11 Chwefror]] [[1992]] <td> [[15 Rhagfyr]] [[1994]]

<tr bgcolor=#DDEEFF><td>9.<td>[[John Bruton]] <td> [[Fine Gael]] <td> [[15 Rhagfyr]] [[1994]] <td> [[26 Mehefin]] [[1997]]

<tr bgcolor=#DDFFDD><td>10.<td>[[Bertie Ahern]] <td> [[Fianna Fáil]] <td> [[26 Mehefin]] [[1997]] <td> [[7 Mai]] [[2008]]

<tr bgcolor=#DDFFDD><td>11.<td>[[Brian Cowen]] <td> [[Fianna Fáil]] <td> [[7 Mai]] [[2008]] <td>