The Scotland midfielder has penned a deal to 2028 to end speculation over his future.
Bologna announced on Friday: "Bologna Fc 1909 announces that it has reached an agreement with midfielder Lewis Ferguson for the extension of the contract until 30 June 2028, with the option for an additional season."
Ferguson joined Bologna from Aberdeen in 2022.
Now club captain, the midfielder has made a successful return this season from a knee injury late into the last campaign.