The party garnered about 23 per cent of the popular vote, down from 27 per cent in the September 2012 election.
"The Coalition, more than ever, is here to stay," Legault told party supporters in his riding of L'Assomption.
"The beautiful story is only just starting."
Legault, who defeated former Bloc Quebecois MP Pierre Paquette to win his own riding, will be surrounded by many of his trusted lieutenants in the national assembly.
Nathalie Roy, Gerard Deltell, Eric Caire, Francois Bonnardel and Marc Picard were among those re-elected.
While the Coalition lost some ridings in the Quebec City area, it compensated by winning others in and around Montreal.
It kept 13 of the 18 seats it had at dissolution.