We went by Metro from Paris to Saint Denis, a quick [approx 20mins] ride on Line 13.
About a 5min walk to the Basilica
You can also take the RER - line D and Tram line T1
If coming from Paris by Car, take the motorway A 1 Towards Lille, exit Saint-Denis Basilica
Basilica of Saint-Denis
1, rue de la Legion d'Honneur
The suburb of Saint Denis is reached from Paris quite easily. Although many local trains departing from la Gare Paris-Nord pass through Saint-Denis, the best way to get to Saint Denis is by Metro or RER. Both take around 15 minutes from the heart of Paris. Metro line 13 stops just outside the Cathedral, and is therefore more convenient, while the RER D stops at the Saint Denis railway station, a good 10 minute walk from the Cathedral.
As Saint Denis is a city very close from Paris it's perfeclty well linked by Métro (subway), RER (metropolitan trains) and Tram (tramway). In spite of you don't asked for a new ticket you need to enter in the transport system with a ticket valable for zone 3, so you're regular ticket for Paris (1 and 2 zone) is not OK for Saint Denis. Pay attention, because if don't have it you will not be able to exit once you will arrive at saint Denis.
If you're going to the city centre is much better take the 13th line of the subway. Pay attention! There are two ends for the same direction and you must ride the metro going direction St. Denis-Université. It's marked with a arrow in the stations and also in the trains, both inside and outside. This line has 4 stations in Saint Denis: Carrefour Pleyel, Saint-Denis - Porte de Paris, Basilique de Saint-Denis (in the center of town, near the Saint Denis Basilica), and Saint-Denis - Université. The RER D arrive to Saint Denis too.
If you're choise is the Stade de France (the big National Stadium), you must better will choose the RER B and take the La Plaine – Stade de France station, or the RER D stopping at Stade de France - Saint-Denis.
Finally, there is a tramway line and a Transilien (regular train) service.
From Saint-Denis station, historically the only rail station in Saint-Denis before the arrivals of the Metro and the RER, we took the tram in order to go to the Basilica.
We've got off the tram at the 3rd station - Basilique de Saint-Denis - Hotel de Ville.
We arrived in Saint-Denis by RER and after a short walk on the nice streets we decided to go back by metro.
Saint-Denis is served by four stations of Line 13: Carrefour Pleyel, Saint-Denis - Porte de Paris, Basilique de Saint-Denis (in the center of town, near the Basilica), and Saint-Denis - Universite.