Hundreds of people lined up in the rain and humidity an hour before doors opened and the park's mascots welcomed guests in.
Visitors are required to reserve spots in advance due to a reduced capacity of 9,000, as part of the theme park's strict hygiene measures to prevent overcrowding. The park will only gradually increase capacity in late July.
"We understand that there is high demand, as a matter of fact we need to comply with the requirement, I mean, from the government to enhance the hygiene measures and also to implement the social distancing management to make sure that the guest, and the staff, and also the animals, they will be safe when we reopen the park," Ocean Park's Executive Director of Operations and Entertainment, Timothy Ng told reporters.
Hong Kong has managed to keep its coronavirus case numbers low despite it being a densely populated city. The city has 1,109 confirmed cases, most of whom have recovered, and four deaths since the beginning of the outbreak.