The 2016 National Assembly for Wales election was held on Thursday 5 May 2016, to elect members (AMs) of the National Assembly for Wales, later known as the Senedd (Welsh Parliament; Welsh: Senedd Cymru). It was the fifth election for the assembly, the third election taken under the rules of the Government of Wales Act 2006 and the first since the Wales Act 2014.

The governing Labour Party's share of the vote fell by over 7% and 29 Labour AMs were elected, one fewer than in 2011 and two short of an overall majority. Plaid Cymru became the Assembly's second largest party and the official opposition to the Welsh Government with 12 seats, one more than before. 11 Conservative AMs were elected, three fewer than in 2011. Although they did not win a single constituency, the UK Independence Party (UKIP) had seven members elected through the regional lists vote. The Liberal Democrats had only one AM returned, down from five.

The election was held on the same day as elections for the Scottish Parliament, the Northern Ireland Assembly, the Mayor and Assembly of London and in numerous local authorities in England. The by-election for the Westminster seat of Ogmore was also held on the same day. This election and elections to the other devolved chambers were delayed by a year from 2015 to 2016 as a result of the Fixed-term Parliaments Act 2011.

In general elections for the National Assembly for Wales, each voter has two votes in a mixed member system. The first vote is for a candidate to become the Assembly Member for the voter's constituency, elected by the first past the post system. The second vote is for a regional closed party list of candidates. Additional member seats are allocated from the lists by the d'Hondt method, with constituency results being taken into account in the allocation. The overall result is approximately proportional.

Previously it was not allowed to stand in both a constituency and a regional list, but this rule was abolished by the Wales Act 2014. The Act also introduced a ban on dual mandates with the House of Commons: an Assembly Member is no longer allowed also to be an MP.

British, Irish, Commonwealth and European Union citizens living in Wales aged 18 or over on election day were entitled to vote.

The following, previously incumbent AMs, did not run for re-election:

NB: AMs in office (i.e. incumbents) before the election are bolded. Winners are highlighted with party colours.