Twelvetree will begin the new role on 10 April and report to the board of the Premier League club.
He was previously director, marketing content (communications, partnerships and digital marketing) and executive director, brand and central marketing at Visa.
Before joining Visa he spent 11 years in a series of marketing roles at Barclays Bank and Barclaycard, becoming global brand director of Barclaycard in 2009.
Earlier in his career, he led the marketing for the launch of Heat magazine at its then owner, Emap.
After a miserable season in 2015-16, Chelsea are today eight points clear at the top of the Premier League, and are hot favourites to regain the title they last won in 2015.