WI members have worked on the display since last August.
The display was commissioned with support from England Rugby and West Northamptonshire Council, and has grown in scale since it was first proposed.
Lynne Abraham, of East Hunsbury WI, said: ” We’re the only town out of all the places the games are taking place.
“We want the world to see Northampton on the map. I’m quite emotional about it… [the display] makes me so proud.”
Carolyn Stone, of Hunsbury Hill WI, said: “We’ve got to meet lots of ladies from other WIs through this project… It was worth doing to show what the WI is capable of.”
The Women’s Rugby World Cup will begin on 22 August, when hosts England face the United States.
Franklin’s Gardens is one of eight venues across England hosting matches.