But ex-Chelsea boss Ranieri, whose side host West Brom on Tuesday (19:45 GMT), believes the Londoners can end their 55-year wait for a top-flight title.
"Tottenham are strong in every situation," said the Italian.
Spurs could go top with a win at West Ham on Wednesday, should the Foxes slip up against West Brom.
Arsenal are three points adrift of their London rivals in third, with Manchester City another four points back in fourth, albeit with a game in hand.
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"Everyone is speaking about Leicester but nobody about Tottenham," he said.
"Tottenham, in my opinion, are favourites. When they defend and when they attack, they know what they want.
"We are the surprise, that is fantastic, a good energy, but if we are realistic the real competitors are Manchester City, Arsenal and Tottenham."
'You'd put this in front of Forest'Ranieri may be reluctant to speak about his side's title hopes, but West Brom counterpart Tony Pulis is hoping the Foxes can hold off their rivals.
He told BBC Radio 5 live: "The divide between the big clubs and everyone else is enormous. It would give everyone hope. You want to see the underdog do well.
"It would be a wonderful, wonderful achievement. I hope they see it through."
Pulis believes a Leicester triumph, a year after fighting relegation, would eclipse the achievements of Brian Clough with Nottingham Forest in 1978.
Clough took Forest to their first - and only - domestic league title a year after winning promotion to the top flight, later winning two European Cups.
"It'd be that big," said Pulis. "But it was different then. The divide then wasn't as great as the divide is now between those who've got it and those who haven't got it.
"The Premier League wasn't in place, so you'd most probably put this in front of that."