Wheldon, who left Barclays last month after three years as head of brand, reputation and citizenship, will join the bank in July.
He will replace director of communications, Andrew McLaughlin.
Joining the executive committee, he will be responsible for all aspects of brand, marketing, communication, and corporate responsibility reporting directly to RBS CEO, Ross McEwan.
"The creation of this position sends a clear message about how we want to do business and backs up our intent to move the bank on to a new footing," said McEwan.
"Last year we set out on a clear path to make RBS the number one bank for customer service, trust and advocacy and have already made progress in becoming a simpler and fairer bank that puts the needs of customers at the core of everything we do."
Prior to joining Barclays, Wheldon was global brand director for Vodafone and held senior roles at WPP and Coca-Cola.
As a result of his departure, Barclays said they had taken the decision to split his role in two. Diane Eshlemen, formerly on Barclays procurement team, will take up the role of head of citizenship and repuatation. Barclays is recruiting for a head of brand, insight and sponsorship, a spokeswoman said.