Vardy has notched nine goals in as many matches to date in the Premier League, and he currently tops the scoring charts in England's top-flight.
The 28-year-old forward has been a revelation so far this term, and Ranieri has hailed the striker's performances.
"If I was a player I'd think 'Oh, Jamie can score, Jamie can score' and this is important," he said to the Southern Daily Echo.
"He's got good stamina, and it's good to think during the match 'Jamie can score'.
"He's fantastic. He ran a lot, pressed a lot, but also at the right moment was very, very clear to choose the best solution."
Vardy scored twice in Leicester's most recent match, as they came back from 2-0 down to pick up a point against St. Mary's.
The Saints had appeared to be heading towards a comfortable victory, but Vardy first nodded in a header, before slamming in a late equaliser.
It further highlighted the confidence that he has at the moment, with the former Fleetwood Town man continuing to earn a huge amount of plaudits.
If Vardy can keep up his fine scoring run, Leicester will be well placed to continue their excellent form, which has seen them rise to fifth spot in the Premier League table.