The 52-year-old was sacked by Reading on March 12 despite leading the Royals to promotion last season.
And he is close to making a quick return to the game at Elland Road as the replacement for Neil Warnock.
Warnock parted company with Leeds after it became clear the Whites would not reach the play-offs.
McDermott’s first task will be to steer the Yorkshire side clear of relegation danger.
They are 17th in the Championship but are just five points above the bottom three with a crunch clash with fellow struggles Sheffield Wednesday on Saturday.
And McDermott is expected to take the reins ahead of that match in a bid to boost his new team who have not won for seven games.