Paul Chambers hit the headlines in his native England earlier this year (10) when he was arrested for writing a message on the site threatening to blow Robin Hood Airport in Doncaster, northern England "sky high" after snowy conditions closed the building and he missed a flight.
He was found guilty of sending a menacing electronic communication and Fry, famous for his love of Twitter, was outraged by the conviction - especially as Chambers insisted the post was meant as a joke.
Chambers lost an appeal earlier this month (Nov10) and the judge ordered him to pay $4,500 (£3,000) worth of legal costs, but Fry has now offered to pay the fine out of his own pocket.
He writes, "Paul J Chambers. My offer still stands. Whatever they fine you, I'll pay."