The two most prevalent pronunciations of "Caribbean" outside the Caribbean are n/ (BEE-ən), with the primary stress on the third syllable, and n/ (RIB-ee-ən), with the stress on the second. Most authorities of the last century preferred the stress on the third syllable. This is the older of the two pronunciations, but the stressed-second-syllable variant has been established for over 75 years. It has been suggested that speakers of British English prefer n/ (BEE-ən) while North American speakers more typically use n/ (RIB-ee-ən), but major American dictionaries and other sources list the stress on the third syllable as more common in American English too. According to the American version of Oxford Online Dictionaries, the stress on the second syllable is becoming more common in UK English and is increasingly considered "by some" to be more up to date and more "correct".
The Oxford Online Dictionaries claim that the stress on the second syllable is the most common pronunciation in the Caribbean itself, but according to the Dictionary of Caribbean English Usage, the most common pronunciation in Caribbean English is in fact on the first syllable, n/ (KARR-ih-bee-an).