Thousands of people are expected to gather in central London as part of annual St Patrick's Day festivities.
The St Patrick's Day Festival is organised by the Mayor of London
A parade of bands, floats and stilt walkers will make its way through central London starting in Park Lane and finishing in Whitehall Place.
Trafalgar Square will also showcase Irish music and dance, from traditional to contemporary.
The festival has been organised by the Mayor of London Ken Livingstone and sponsored by Tourism London.
"London boasts one of the largest Irish communities outside of Ireland," said Mr Livingstone.
"The St Patrick's Day festival and parade are an opportunity for all Londoners to experience the breadth of Irish culture and what it has brought to this city."
St Patrick's Day is on the 17th of March, but celebrations were being held around the country on Sunday.