As per Football Insider, the 34-year-old completed a medical with the Rams yesterday ahead of the move.
Their report states that although the deal is not done yet, Derby are hopeful it will be finalised soon, dealing a blow to Chris Wilder and Middlesbrough in the process.
The former Republic of Ireland international was released by Sheffield United at the end of last month upon the expiry of his Blades contract.
That move followed an injury hit campaign last term in which the 34-year-old made just 19 Championship appearances.
The season prior to that, though, the experienced forward netted eight times in the Premier League in a struggling Blades side.
Quiz: Are these 20 Derby County transfer facts true or false?
This development certainly comes as somewhat of a surprise.
On paper, a move to Middlesbrough seemed the obvious choice for McGoldrick this summer given they are in the Championship and it would see him re-unite with his former boss Chris Wilder.
However, taking a step back from that personal relationship, a move to Derby County may actually be best.
It would likely offer him a much greater chance of playing regular football week in week out, and you can see the 34-year-old bagging a load of goals down in the third tier.
Come this time next season, we could look back at this move as one of the key deals that played a part in Derby earning themselves an immediate return to the Championship.