Paterson will continue in her role for a "few weeks" before stepping down, following the announcement of her resignation via an internal memo. She had been in the role for two years.
During her tenure as marketing director, she led a brand relaunch through the 'I Did That' campaign and developed new customer-centric channels, including YouTube, where the retailer hosts hundreds of how-to films on home improvement.
A B&Q spokesman has insisted the marketing director role will keep its place on the board and report directly to chief executive Martyn Phillips.
In the meantime, brand director David Hutchinson will take over as interim marketing director.
A decision has not yet been taken on whether he will assume the role full time.Follow @mattchapmanuk