It will be the first time a New Zealand Prime Minister has visited Fiji in four years and comes during the 50th anniversary of Fiji's independence.
Ms Ardern says Fiji is New Zealand's largest trading partner in the Pacific, visited by 200,000 New Zealand tourists a year.
She will visit Suva, Nadi and Lautoka on her three day trip, which will focus on climate change, supporting women and strengthening democracy.
Ms Ardern will meet with her counterpart Frank Bainimarama, address students at the University of the South Pacific and meet Fijian women leaders in government, business and civil society.
She will also pay respects to the three Fijian nationals killed in the Christchurch terror attacks.