Historic trip to begin with tree-planting ceremony at Aras an Uachtarain
President Mary McAleese officially welcomes the royal party to Aras an Uachtarain, where the queen will plant a tree in the grounds of the Aras near the Peace Bell.
At the Garden of Remembrance in Dublin city centre, the Queen will lay a wreath in memory of all those who gave their lives in the cause of Irish Freedom.
Her busy day's schedule will end with a visit to Trinity College.
The queen will be treated to a panoramic view of Dublin city when she visits the Gravity Bar at the country's top tourist attraction, the Guinness Storehouse.
Taoiseach Enda Kenny will greet the monarch when she visits Government Buildings.
The second wreath-laying ceremony during the queen's trip takes place later at the Irish War Memorial Garden at Islandbridge, which is dedicated to the memory of 49,400 Irish soldiers who died in the 1914-1918 War.
It will be followed by an historic visit to Croke Park, where she will be treated to Irish dancing and will be shown some of the GAA's precious silverware, including the Sam Maguire and Liam MacCarthy Cups.
Later that night, more than 160 guests will attend a state dinner in Dublin Castle. The queen and Mrs McAleese will deliver speeches.
Guests at the dinner will include Taoiseach Enda Kenny, senior cabinet members, former presidents and Taoisigh and senior members of the judiciary.
The queen visits the National Stud in Kildare. Later, she will host Mrs McAleese at a "return event", with a programme showcasing the best of Irish and British fashion and a concert at the National Convention Centre in Dublin, featuring a number of acts including The Chieftains, Westlife, former 'X Factor' contestant Mary Byrne and Riverdance.
The royal tour moves on to Cashel, then Cork for a visit to the English Market and the Tyndall Institute.