Duncan Alexander Webb is a New Zealand lawyer and politician. He was elected as a Member the New Zealand House of Representatives for Christchurch Central, representing the Labour Party, in the 2017 general election.

The 2017 New Zealand general election took place on Saturday 23 September 2017 to determine the membership of the 52nd New Zealand Parliament. The previous parliament was elected on 20 September 2014 and was officially dissolved on 22 August 2017. Voters elected 120 members to the House of Representatives under New Zealand's mixed-member proportional (MMP) voting system, a proportional representation system in which 71 members were elected from single-member electorates and 49 members were elected from closed party lists. Around 3.57 million people were registered to vote in the election, with 2.63 million (79.8%) turning out. Advance voting proved popular, with 1.24 million votes cast before election day, more than the previous two elections combined.