Modesto begins his new role in November and will be responsible for helping to build closer ties between the agency's seven offices in the region.
He will continue to be based in the agency's Chicago office and will report to the DraftFCB chief executive and president, Laurence Boschetto.
Modesto has spent almost 30 years with DraftFCB. He was appointed the co-president of DraftFCB's Chicago office in 2003 and has since helped the agency win new business from brands including Kraft, MillerCoors and MoneyGram.