The 28-year-old, who has scored 31 goals in 98 appearances for the MLS side, has signed a temporary deal which runs until May 6.
And Canaries boss Hughton has expressed delight at Kamara's capture, after missing out on signing Celtic forward Gary Hooper.
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|5/2||Gary Hooper is 5/2 to sign for Norwich before 1 February 2013 with Bet Victor
"There's no doubt it's a big jump to make into the Premier League. It is an exciting challenge both for him and us here at the club to prove his talent.
"Kei also adds some valuable competition upfront alongside the current striking options we have here at the club.
"I don't think it's about the league they play in. We would always have to have good reasons for liking a particular player."