Coventry clash awaits if Saints see off Clermont Auvergne
The stadium is chosen by EPCR, the organisers of the competition, and must be at a neutral venue in the host country.
Another option would have been stadium:mk, but MK Dons host Leyton Orient that weekend, meaning there is less flexibility for when the game could be played.
Saints played their Heineken Cup semi-final against Perpignan in Milton Keynes back in 2011, but they do have history of playing a final-four tie at the Ricoh Arena.
They faced Wasps, who were the team holding home advantage on that occasion, in Coventry in a Heineken Cup semi-final in 2007.
Should Clermont beat Saints at Stade Marcel Michelin this weekend, they will play the semi-final at Stade Geoffroy-Guichard in Saint-Etienne.
Champions Cup semi-finals - 18/19 April
RC Toulon v winners Leinster Rugby v Bath Rugby
Stade Vélodrome, Marseille (capacity: 62,895)
Wasps v winners Leinster Rugby v Bath Rugby
American Express Community Stadium, Brighton (capacity: 30,750)
ASM Clermont Auvergne v winners Racing Metro 92 v Saracens
Stade Geoffroy-Guichard, Saint-Etienne (capacity: 39,774)
Northampton Saints v winners Racing Metro 92 v Saracens
Ricoh Arena, Coventry (capacity: 32,609)