The 30-year-old - a previous transfer target for Latics under Paul Cook in 2019 - joins for a fee which chairman Talal Al Hammad confirmed was less than the reported £30,000, because the Rams are in administration.
"We wish Graeme well and look forward to welcoming him to the squad this week," read a Latics statement.
Shinnie was Derby's player of the year last term.
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