The party is set to host its larger autumn conference in Brighton this month, from 22-26 September 2012, at the Hilton Brighton Metropole Hotel.
More than 2,500 delegates are expected to attend the spring Conference bringing an estimated £2m of economic benefit to the city.
Carla Rollin, director of business development, Hilton Brighton Metropole, said: "To have been selected for both the autumn and now the spring Liberal Democrat conference is testament to Brighton as a first rate event destination and the superb guest experience available at hotels such as Hilton Brighton Metropole. It's a huge boost for the city and is thanks in part to a close collaboration with Visit Brighton in building strong relationships and demonstrating flexibility."
Julia Gallagher, Visit Brighton's Convention bureau manager, said: "It's great to know that, aside from the nitty gritty of policy making and debate, delegates enjoy coming to Brighton. It's been a challenging year for many businesses because of the long spell of appalling weather but ongoing refurbishment programmes and investment in the city's venues has helped to keep business trade buoyant. We have a full programme of cultural and creative activities to complement our business offering and we know this all helps to make Brighton an attractive proposition."