The 27-year-old has scored eight goals since joining the principality club from Atletico Madrid in the summer, helping them to second in Ligue 1 after 11 games.
Three points against Lille in Sunday's fixture at Stade Pierre-Mauroy will see them draw level with leaders Paris Saint-Germain once again, and Ranieri has urged his players to redouble their efforts to provide for the £52m frontman.
"The team should offer more support to Falcao and give him the ball more," Ligue1.com quotes the 62-year-old as saying.
"We know that the last pass can be difficult, but we also know that he can score goals and can turn things around if we use him well.
"This is the task that I am giving to my squad. Falcao is a player who can strengthen our confidence."
Falcao scored 28 goals in La Liga last season.