At some point after graduating law school, Laurel Lance began living at the apartment.
Tommy Merlyn periodically spent the night with Laurel at the apartment during their "lapse". He eventually officially moved in with Laurel after being cut off by his father. Several months later, Tommy left after breaking up with Laurel.
When Thea Queen recovered from her near-death experience at the hands of Ra's al Ghul, she moved into the apartment with Laurel.