Rotherham announced the departure of head coach Leam Richardson this morning after their relegation from the Championship was confirmed earlier this month.
Evans returns to the New York Stadium alongside assistant Paul Raynor, with the duo signing contracts that will run until 2027.
The pair led the club to back-to-back promotions from League Two to the Championship between 2012 and 2014 and will take charge of their fixture against Birmingham on Saturday.
Evans departs Stevenage after just over two years at the club, taking them from League Two to the top half of League One.