The Brodie helmet is a steel combat helmet designed and patented in London in 1915 by John Leopold Brodie. A modified form of it became the Helmet, Steel, Mark I in Britain and the M1917 Helmet in the US.

Here an example of such a helmet. The Helmet comes with full liner and retains even the use tag. Chin strap snapped by present. Helm is named on inner rim: "CO.D. 310th INF MAIL ORDERLY 1st CL PVT WILLIAM E.McELROY 2941689". No visible maker's mark.