Among those taking part is the Rugby World Cup team where you’ll have the chance to get up close and personal with some Irish rugby legends and the Webb Ellis Cup.
And if that’s not enough, sports fans can also drop by to meet the London Irish Rugby Club team at their stall.
As well as that, The Irish Post will be celebrating 45 years in business throughout 2015, so come meet the team and get your hands on free goodies.
Meanwhile O2 and Tourism Ireland, two of the Festival’s sponsors, will be there on the day too —so make sure to look out for them at Trafalgar Square.
Among the other community stalls will be the Irish Cultural Centre and the London Irish Centre, the Irish in Britain charity, Irish Voices and Votes for Irish Citizens Abroad, a campaign by London Irish community members calling for the right of Irish citizens living outside the island of Ireland to vote in general elections in the Republic.