AKQA won the business after a pitch against an undisclosed number of agencies, believed to include the McDonald's digital roster shop Tribal DDB.
AKQA will produce a strategic campaign to break in the new year.
The McDonald's global chief marketing officer, Mary Dillon, said: "We are pleased to partner with AKQA to develop a global digital marketing strategy to strengthen further the McDonald's brand. AKQA will work closely with our outstanding network of local digital agencies around the world."
Diageo has also appointed AKQA to handle its digital account following the appointment of its first global digital marketing director, Michelle Klein.