Blending heritage and modernity, the hotel, which was conceived by Woods Bagot, has 108 rooms and suites.
Visitors can choose from one-and-two-bedroom suites, either within the restored 1875 limestone building or in the newly constructed wing that has private outdoor terraces.
Penthouses will also be opened later this year.
It offers a guest-only Mediterranean pool deck for lounging, swimming, and relaxing from sunrise to sunset, with views of the waters of Sorrento and Port Phillip Bay.
It provides a selection of drinks and eatable items to enjoy under cabanas or poolside chaises.
The hotel features a 24-hour fitness centre, two restaurants, a beer garden, front bar.
Its Grand Ballroom offers a majestic setting for private events.
Due to open later this year, Aurora Spa & Bathhouse will act as a sanctuary for recharging within a thermal bathhouse and wellness centre.
IHG Hotels & Resorts managing director for Australasia & Pacific Matthew Tripolone said: “We are in one of the most exciting periods of growth and transformation across our Luxury & Lifestyle portfolio.
“The opening of InterContinental Sorrento Mornington Peninsula is a wonderful milestone in our vision to bring the InterContinental Life to the world’s most sought-after destinations, and we have no doubt that the brand new experiences will offer a memorable stay for both locals and international visitors alike.”