Belle is fairly regular at the Disney Parks.
At Walt Disney World she can normally be found in France at EPCOT, and sometimes at the Akershus Restaurant. In the Magic Kingdom she is normally in the Town Square Theater. She can sometimes be found at Cinderella's Royal Table.
In Disneyland California Belle can often be found at the Princess meet 'n' greet area in Fantasyland, and the Ariel's Grotto character dining at DCA.
In Disneyland Paris she is often at the Princess Pavilion and at the Auberge de Cendrillon character dining in Fantasyland.
In Tokyo Disneyland and Hong Kong Disneyland Belle appears in both their Fantasylands quite regularly.
Belle also appears on selected DCL sailings. You should check your Personal Navigator for details.