The Foyle MP named Soldier F during a debate in the House of Commons on the Armed Forces Bill on Tuesday afternoon.
The former paratrooper is also facing five attempted murder charges.
He had been granted anonymity by the judge hearing the case.
Speaking on Wednesday in the Commons, Speaker Sir Lindsay Howell said Mr Eastwood “broke no rules”.
“As members of this house, we enjoy freedom of speech,” said Sir Lindsay.
“A member may state whatever they think fit in debate and that the member is protected by parliamentary privilege.”
However, Sir Lindsay told MPs that freedom of speech “must be used responsibly”.
“Privilege places significant responsibility on parliamentarians to exercise it in the public interest and presumptions should be that court orders are respected in parliament,” he said.
“When a member does not comply with one, he or she can demonstrate that it is in the public interest.
“It is for others to judge whether or not the actions of the honourable member for Foyle were indeed in the public interest.”
After naming Soldier F on Tuesday, the Mr Eastwood said: “For 50 years he has been granted anonymity and now the government want to grant him an amnesty.
“No one involved in murder during the Troubles should be granted an amnesty.”