The Arms Amendment Act 2019 is a New Zealand bill that amends the Arms Act 1983 to ban semi-automatic firearms, magazines, and parts that can be used to assemble prohibited firearms. It was introduced by Labour cabinet minister and Member of Parliament Stuart Nash in response to the Christchurch mosque shootings. The Bill passed its third and final reading on 10 April 2019, receiving royal assent the following day. The Arms Amendment Bill was supported by all parties represented in parliament except the opposition ACT Party.