The Dutch star had not officially joined Fenerbahçe despite being presented to the fans as one due to his paperwork not being finalised at the time.
Van Perise had already signed a three-year contract with the Yellow Canaries but did not have his international registration certificate.
The statement read: “Manchester United confirms that the transfer of Robin van Persie to Fenerbahce has now been fully completed. While the striker was presented to the media by the Turkish club earlier this month, the paperwork required in order to release his international registration certificate was not finalised until this week.”
Van Persie joined Luis Nani as the second former United player to join Fenerbahçe this summer. The Istanbul giants have made a total of eight transfers over the transfer window.
The Netherlands international has been included in the 24 man squad that will face Shakhtar Donetsk in the Champions League preliminary play-off round at the end of the month.