Striker Kane leads the race for the Premier League's golden boot with 25 goals while midfielder Alli, 20, has scored 10 times and claimed 12 assists in his debut season for Spurs.
“England have a good chance of doing very well in the competition. For me, Dele Alli and Harry Kane can be the difference,” Beckham told British media at the London launch of his old club Manchester United's new away kit.
“Dele plays week in week out for Tottenham, he's not scared to play, not scared to do things, he's a joy to watch.”
Beckham, England's most capped outfield player, said partnering Wayne Rooney up front would help the 22-year-old Kane develop his game.
“Harry is a very talented player and he can learn from the likes of Rooney,” Beckham explained.
England are looking for their first major trophy since the 1966 World Cup and face Russia, Slovakia and Wales in Euro 2016 Group B in France.
Manager Roy Hodgson will name his squad for the tournament on Monday.
Original source: Beckham backs Spurs duo to inspire England at Euros