The Whanganui branch of the New Zealand Law Society had its beginnings on 23 October 1913 when the Wanganui District Law Society was founded. This became the Whanganui branch of the Law Society on 1 February 2009.
Governance is by an elected Branch Council, consisting of the branch President, the Vice-President and from three to ten members. The President represents the branch on the New Zealand Law Society's Council.
The branch functions include representing and serving the interests of local members, upholding the fundamental obligations imposed by the Lawyers and Conveyancers Act 2006 on lawyers who provide regulated services, promoting collegiality within the branch and assisting and promoting law reform.
The Whanganui branch area includes the centres of Bulls, Hunterville, Marton, Ohakune, Raetihi, Taihape, Waverley and Whanganui.