The section contains more than 4,000 marine animals in 13 themed displays featuring forest foliage, mists and waterfalls.
Creatures featured in the exhibit include a pair of six-foot West African dwarf crocodiles sisters, 15 poison arrow frogs and 30 piranhas.
The Sea Life London Aquarium general manager of events Michael Aldridge said: "Guests will literally be within snapping distance of the crocodile sisters. The new Rain Forests of the World exhibit offers event organisers another exciting opportunity for events at the London Aquarium."
The new area is available for events for 500 or more delegates.