Could alien civilizations be watching Earth right now?

Yes, it’s possible in principle, but we have no evidence that any alien civilization is watching Earth right now.

The most realistic meaning of “watching” would be detecting Earth remotely, not seeing us in real time with detail. A sufficiently advanced civilization could potentially notice signs such as Earth’s atmosphere, city lights, radio leakage, or other technological signals—if they are nearby enough, looking in the right way, and have sensitive instruments.

Two big caveats matter:

1. Distance creates delay: if a civilization 100 light-years away observes Earth, they see Earth as it was 100 years ago.
2. Detecting Earth is much easier than detecting humans: Earth has been visibly life-bearing for billions of years, but our strong technological signals are recent and relatively faint on cosmic scales.

So the best short answer is: alien civilizations could be observing or detecting Earth right now, but there is currently no confirmed evidence that anyone is doing so.