Gordon Strachan departed the post by mutual consent after Scotland failed to reach the play-offs in World Cup qualifying, drawing their final must-win game against Slovenia.
And Mackay, who had been working as the Scottish FA's performance director, has been handed the first team reigns on a temporary basis.
"The recruitment phase [for a permanent manager] begins next week," SFA chief executive Stewart Regan said, as reported by the BBC. "It's difficult to put a timescale on replacement.
SCOTLAND | Malky Mackay will take interim charge of Scotland for our International Challenge Match against Netherlands on 9 November. pic.twitter.com/xh6JjGAYDc— Scottish FA (@ScottishFA) October 13, 2017
"We believe we can compete [financially] to get the right person for the manager's job. We want someone capable of getting to Euro 2020."