RER line C from Paris will take you to Versailles Château - Rive Gauche train station, which is only a 10 minutes’ walk to the Palace. If you're taking the RER C line, take trains “VICK” or “VITY” to Versailles Rive Gauche.
SNCF trains (Line N) from Gare Montparnasse in Paris will take you to Versailles Chantiers train station, which is an 18 minutes’ walk to the Palace.
SNCF trains (Line L) from Saint - Lazare in Paris will take you to Versailles Rive Droite train station, which is a 17 minutes’ walk to the Palace.
The RATP bus line 171 runs between Pont de Sèvres (last stop on line 9 of Paris metro) and the Palace of Versailles. It usually takes 40 minutes to travel between the two bus stops, depending on traffic.
The fastest route between Paris and Versailles by road is the N118. If you're leaving from central Paris, head west along the Seine taking the D910 until you get to Pont de Sevres. Continue over the bridge and keep left to continue over N118. Follow the signs and you will be at the Palace of Versailles in under 40 minutes.