Black Country MPs joined forces to put the region in the national spotlight as they took the flag with them on a trip to the Commons.
A range of events will be taking place on Friday as part of Black Country Day, celebrating the region's history and culture.
The day is part of the Black Country Festival, now a regular summer fixture.
It comes after a series of events were held at the weekend, including a huge celebration at one of the region's most popular spots - the Black Country Living Museum.
Fun days were also held in Netherton and Lower Gornal.
Dudley North MP Ian Austin, West Bromwich West MP and Labour deputy leader Tom Watson, Wolverhampton South East MP Pat McFadden and Adrian Bailey, MP for West Bromwich West, gathered outside Parliament in London to display the famous flag, which is expected to be on show across the Black Country on Friday.
Mr Austin said: “I’m from Dudley and no one is prouder of the Black Country than me, so I was determined to celebrate Black Country Day by flying our brilliant flag here in Parliament this week.
“I want people in London to know that Dudley lit the spark that fired the industrial revolution, changing not just the Black Country, or even Britain, but the whole of the world. It was the Black Country that put the great into Great Britain.
“Our flag, Black Country Day and the festival as a whole is fantastic because it brings our whole community together to celebrate the greatest place in the country."