Eric Pickles, Secretary of State for Communities and Local Government, has approved Chester Zoo's plans for its Natural Vision project.
Cheshire West & Chester Council approved the plans in September and they were then automatically referred to the Secretary of State.
Mark Pilgrim, Chester Zoo's director general, said: "We are delighted with the Secretary of State's decision. The announcement is the culmination of many years of hard work and extensive public consultation.
"In light of the decision, the zoo will now take stock of the project as a whole and agree the best way forward from here.
"We would like to thank the organisations, particularly the NWDA, other bodies, individuals and community groups that have supported us this far. We would wish to reassure them and our neighbouring communities that we will continue to work with them as the project unfolds."
Plans include a 'heart of Africa' biodome building, entrance village, a hotel and expansion of the main entrance and car park.
The overall masterplan is expected to cost in the region of £225m and the zoo is currently exploring sponsorship and other funding streams.
Hill Dickinson advises Chester Zoo. Robin Jones, partner at law firm Hill Dickinson's Chester office and client relationship partner for the zoo's Natural Vision project, said: "This announcement is a significant milestone in bringing this landmark development to fruition. Hill Dickinson has been the legal advisor for the Natural Vision project for nearly four years now and we are proud to be involved in such an exciting scheme, which will not only benefit the zoo itself, but the community in Chester and the wider region."