Retail worker. Thousands of years of “Civilisation” and most people still haven’t worked out that the sign with a product description and a price sitting on the shelf with an item is clearly the price tag…
Some foreign aid work takes people for long periods into very remote areas and small communities, same with missionary work, I don’t know if that qualifies as removed from civilization.
Monks? Some monasteries are pretty isolated.
How how about the guy who went to the Marianas trench… once… for 20 minutes? 
Clowns. People prefer not to see clowns. Some people are quite emphatic on the subject.
Myself almost said what I was thinking: prospector. Diamonds in the Amazon or opals in Australia should keep you away from everything for a while.
In Australia, you could get an ‘agricultural’ job that might well see you stationed 300km from the nearest dirt-road intersection. I’m thinking mine-worker in Western Australia, shearer/fencer in western NSW, or cattle-musterer in FNQueensland.
You are most certainly removed from civilization in these regions/occupations.
My brother-in-law is a timber cruiser. He’s had contracts that involved camping out in the woods every night for several months, and not seeing another human being for the duration of that time.
It seems to suit him, somehow.
Unabomber.
Being in the Army can be pretty uncivilized. Not lonely, just uncivilized.
Working at state or national parks and refuges can keep you well secluded. You still have to radio in and respond to people, but you don’t have much contact. Lighthouse keeper was very secluded, but I don’t know how many still have keepers instead of automated systems.