Galtier's side are currently two points behind Lyon with four games left, which means that third place is a possibility with a strong finish to the season.
"We want to go and get third place," he told Ligue1.com. "It is an ambitious objective but a realistic one given that we are currently fourth in the standings.
"There are four teams competing for third place - Lyon, Lille, Nice and ourselves. We need to keep playing the way we have been, with the same enthusiasm. We mustn't have any regrets.
"We have a difficult run-in but it is not insurmountable. These four matches will be decisive but we have already shown that we can perform on such occasions."
Saint-Etienne face Bordeaux on Friday night.