No, you will not get frequent flier credit if you do not fly. Irrespective of whether you check-in or not. Even if you go on board and then decide not to fly, you will be unloaded from the manifest and will not get credit*. Airlines are required to know exactly who is on board for a multitude of reasons, some of which are regulatory, and some of which are for accounting purposes. Imagine what would happen if the aircraft crashes and they're not sure who is on board.
* Mistakes happen of course, so it is possible for you to get credit for phantom flights just as much as it is possible to get no credit for flights you have flown. I've received plenty of them!
Update responding to comments:
A bit about why airlines don't allow mileage accrual without taking a flight.
Taking a flight purely for the purpose of a gaining the benefits tangential to the actual journey is termed Mileage Running. People do it because in certain circumstances, it could be possible to earn more benefits than the cost of the flight. This may be in the various different types of miles earned - redeemable (RDM) or qualifyfing (EQM) or segments (EQS) or points (EQP) and in some cases, e.g. BA or VS, Tier Points. Additionally, as Tom points out, there may be very real benefits associated with earning higher frequent flyer status.
If people could do this without actually flying, there would be no such thing as a mileage run any more. Since you actually have to fly, you can't pounce on a cheap deal from LAX to LAS if you are currently at home in London or Paris. Even though the airlines like you to buy tickets for flights you don't take, they don't want you to benefit from that otherwise it would likely screw up their revenue management, amongst other things.
Mileage run - Quora
Thread about gaining miles without flying on flyertalk
Another one on insideflyer
And this one which means this thread is a duplicate...
Can I claim miles if I bought the Tickets but didn't take the flight?