The 1970 Murrumbidgee state by-election was held on 14 February 1970 for the New South Wales Legislative Assembly seat of Murrumbidgee. It was triggered by the resignation of Al Grassby () to successfully contest the federal seat of Riverina at the 1969 election.
The by-election was held on the same day as two others in Randwick and Upper Hunter and used the same boundaries as the state election.
The Country Party's Campaign Secretary was Mrs. G. Barwick and the campaign used the slogan "The Man Who Cares".
In a meeting with the Lake Talbot War Memorial Fund Committee, Williamson committed to "tak[ing] a stand and fight[ing] for the right of the Narrandera people to obtain government assistance for improvements to the Lake Talbot Swimming Pool".
Policy commitments outlined in the campaign included:
The Country candidate, Robin Williamson, held a luncheon at the Hydro Hotel in Leeton with the state Minister for Public Works, Davis Hughes M.L.A. at 12:30pm on 4 February, inviting "citizens of [the] Leeton, Narrandera, Coleambally, and districts" at a subscription fee of $2.
The Labor candidate, Lin Gordon, campaigned on fighting for Murrumbidgee, pointing to his track record as a Shire President. Gordon was positioned as a protest vote against "Minister Beale's Dictatorship"
Issues outlined by the campaign included:
Gordon held a number of events across the electorate during the campaign including:
The Liberal candidate, Ian Davidge, ran on a platform of giving Murrumbidgee a voice within the Askin Governmnet and his own and the government's record.
Arguments made by his campaign included:
The Democratic Labor candidate, Les Kennedy, ran on a platform of "strongly support[ing] the concept of the Lake Mejum Water Conservation Scheme".
<includeonly> Al Grassby () resigned to successfully contest the 1969 election for Riverina.</includeonly>