Ada had OO from Ada 95, though it doesn't look anything like the OO in most mainstream languages of today. In Ada 95, tagged types were introduced which were based on Ada's powerful record types and Ada 2005 introduced interfaces in a style similar to Java. Java and Ada have both taken plenty from each other over the years.
Edited because I was misleading about the introduction of OO.
Edited because I was misleading about the introduction of OO.