Hearts have managed to beat off competition from the SFA to land the 37-year-old after the governing body looked to hire him as their new performance director.
MacPhee is currently assistant manager at Northern Ireland to Michael O’Neill. He was previously the assistant boss to Danny Lennon at St Mirren between 2011 and 2014, which included a League Cup final victory over Hearts in 2013.
Chairwoman Ann Budge said: “I’m excited and delighted, I’ve said that to both Ian and Austin. I think they are a fantastic addition to our team here at Tynecastle.”