"I am looking forward to applying my experience as a mayor, regional councillor and vice-president to this national leadership role to address the challenges [facing] communities across our country.
"Strong local government and local democracy are hugely important for the success of every New Zealander," he said.
"My aims as president are twofold: to drive sector excellence, and to advocate for legislation and policy that enables every community to stand on their own feet and succeed."
Crosby is joined by Whanganui District Council mayor Hamish McDouall, who has been elected vice-president of LGNZ and is a member of LGNZ's National Council.
"It is an absolute privilege to be elected as vice-president under Stuart," he said.
"I'm looking forward to working hard for the sector and every community in New Zealand to enable the best outcomes for them."
Departing LGNZ president Dave Cull congratulated Crosby on his election.
"It is a role I have had the privilege to hold for the past three years, which has allowed me to represent the interests of New Zealand's diverse communities at the highest political levels.
"That work has only been possible because of the support Stuart has lent me as LGNZ's vice president, and I can think of no one more qualified to advocate for the right of ordinary New Zealanders to have a greater say in the decisions that affect their lives."