'Max' was a German unrealised naval plan for a substantial part of its destroyer strength to provide a measure of protection for the right wing of Generaloberst Fedor von Bock’s Heeresgruppe 'B' in an advance along the coast of the Netherlands, Belgium and France in 'Gelb', and to prevent the delivery of British forces from England to France (29 October 1939).

There was no German offensive of this type in the autumn of 1939, however, so the plan proved unnecessary.