Sedan is roughly 200 km from Paris and 10 km south of the Belgian border. By train, Sedan station connects to Charleville-Mézières (about 20 minutes), which has onward services to Reims and Paris. Direct Paris services require a change at Charleville-Mézières or Reims; the journey takes around two and a half to three hours by rail.
By car from Reims, follow the A34 motorway north through the Ardennes — a straightforward 60 km drive. From Belgium, Sedan is reachable via Bouillon and the scenic Semois valley, which makes for a pleasant approach if you have time to meander.
If you are touring the Champagne region, Sedan is a logical day trip or overnight stop from Reims or Charleville-Mézières.