Having won promotion to Ligue 1 last season, Monaco brought in an array of high-profile names who have helped them remain unbeaten in their opening 11 matches of the campaign.
They are level with Paris Saint-Germain at the top of the table, with striker Radamel Falcao topping the goalscoring charts after netting eight goals in 11 starts.
And Ranieri's sights are set on a top-three finish and a return to Europe's elite club tournament.
"The championship is the most important competition," he said. "The objective is making the UEFA Champions League.
"On Sunday against Lille I want to see the best Monaco
"Lille press high, (and) have defended well with only four goals against, but our philosophy is to win."
Monaco travel north on Sunday looking for their fourth victory against Lille in 10 attempts.
