"Are you lost, Ninja? This is the Christian Federation. The Eastern Bloc is over on the other side of the Core Systems."
While no Human military force since the formation of the Earth Federation in 2007 has had a dedicated Marine branch that was even as independent as the US Marines (who were of course actually part of the US Navy), any infantry or other ground-combat force embarked aboard a spaceship is referred to as a Marine. This is actually the original use of the term, for back in the Age of Sail soldiers on board ships were referred to as Marine Infantry, regardless of who signed their paychecks or where they fit on an org chart.
In the Earth Federation, both Light Infantry and Tech Infantry soldiers could expect to spend at least part of their service as part of a Marine Detachment, either on board one of Earth Fleet's warships as honor guards and boarding parties for enforcement of customs regulations, or on board one of their Assault Transports for making landings on hostile planets via Drop Pods, Transit Beacons, or Assault Pinnaces. Of course, Light Infantry forces are more likely to be boarding freighters to search for contraband, and Tech Infantry troopers are more likely to be screaming down from orbit in a Drop Pod to land on a Bug-infested planet, but either branch could find itself in either role.
The Frontier Worlds Territory actually called its entire ground-combat branch of its military the Colonial Marine Corps, so they could be thought of as Marines who occasionally do not serve aboard a starship rather than Soldiers who occasionally do.