The Men's 400 metres T46 event at the 2012 Summer Paralympics took place at the London Olympic Stadium on 4 September.

[1] The T46 category is for athletes who have a single above or below elbow amputation or similar disability, with normal function in both legs.

Prior to the competition, the existing World and Paralympic records were as follows: Competed 4 September 2012 from 10:38.

rule: first 3 in each heat (Q) plus the 2 fastest other times (q) qualified.

PR = Paralympic Record.