Moore, a former Tranmere favourite left Oldham because of "financial reasons" earlier this month after almost guiding them to an unexpected play-off place.
Before moving to The Latics, Moore guided Yorkshire club Rotherham United to two straight promotions which saw them end up in the Championship before getting them relegated back to League One last season.
In his time at Prenton Park, Moore scored 34 goals in the 1975/76 season and after scoring many more goals in his time at Tranmere, secured at £120,000 transfer to Cardiff City.
Moore, 53, is apparently "delighted" at the chance to take the club he supported as a boy back up to the Championship.