The answer is Yes.
US Congress passed an economic stimulus plan to help economic hardship felt by many during the covid 19 pandemic.
The restriction on receiving the money are;
1) Having a valid social security number and that no one claims you as a dependent.
2) Individuals making $75,000 or less (and married and jointly make $150,000or less) will receive the full benefit. If you exceed the amount, phase-out will be applied.
3) You must have filed for 2019 or 2018 US tax return.
If you have filed your 2019 taxes (or filed in 2018) and your forms included direct deposit information, you don’t need to do anything. The IRS will use your account information to direct deposit your check.
So, yes, US citizens who live abroad will be eligible to receive the 2020 stimulus check.