The colour green was spotted across the region Tuesday as residents celebrated their Irish roots and joined in on St. Patrick's Day celebrations.

"It's absolutely crazy. It's been busy since 11 a.m. this morning and it keeps pumping through," said Lauren Hawkins, manager of the Heart and Crown Irish pub in Ottawa's Byward Market.

"We opened at 9 a.m. for breakfast and ever since then, there's been people lining up and we're already at capacity, so it's fantastic," she told CTV Ottawa at midday.

Although St. Patrick's Day is celebrated as a religious holiday in Ireland, many Canadians mark the day by wearing green clothing and drinking green pints of beer.

In the Ottawa Valley, revelers started lining up at 9 a.m. to secure a spot at the Douglas Tavern, where the Irish holiday has been celebrated for more than a century,

Employees expect the tavern, located just west of Renfrew, to be packed with people singing and dancing well into the early morning hours.

Irish settlers played a large roll in building the capital, with many settling in the Ottawa Valley in the 1800s.