The 54-year-old has left Nottingham Forest to return to Villa Park and become Tim Sherwood's new number two, and will be in the dugout for Saturday's visit of Stoke.
MacDonald was previously reserve team manager at Villa and was also caretaker boss in 2010 following the exit of Martin O'Neill.
MacDonald joins first-team coach Mark Robson and performance analyst Seamus Brady as part of Sherwood's new-look backroom team
He had been at Forest since the summer as lead professional development phase coach and took the club's Under-18 side to the FA Youth Cup quarter-finals.
Sherwood said on Thursday he was looking for a long-term assistant to help him rebuild Villa.
He said: "I am still giving thought to the assistant manager, whoever I bring in will be the correct one for myself and the football club
I'll make sure I'll get that one right
I would rather not jump into it
I want someone for the long-term at the club, to help me build it."
Source : PA
Source: PA