The 2021 Engie Open Nantes Atlantique was a professional women's tennis tournament played on indoor hard courts.

It was the seventeenth edition of the tournament which was part of the 2021 ITF Women's World Tennis Tour.

It took place in Nantes, France between 1 and 7 November 2021.

[1] The following players received wildcards into the singles main draw: The following player received entry using a protected ranking: The following player received entry as a special exempt: The following players received entry from the qualifying draw: The following players received entry as lucky losers: