I was injured on the job and filed for workers comp benefits, I was awarded benefits and was recovering from my injury when my employer decided to terminate me. The employer gave no reason. Can I file a lawsuit?

You were still on workers comp and had not returned to work yet ?

The laws on workers comp vary greatly by state in the US, But anywhere I have worked they are not allowed to terminate you till you are released to come back to work, ( if you are released to do so)

I worked with someone who had a problem such as this: he had a seizure behind the wheel driving a tractor-trailer, was out for six months, then was terminated. He had lots of problems with his workers comp claim (and might still be fighting it) through no fault of his own. He received unemployment benefits almost immediately back in 2009; so at least he got that without delay.