At least eight were arrested early Wednesday when police entered Ottawa's Confederation Park to ask Occupy protesters to leave.
The action came after the National Capital Commission, which owns the park, posted a formal notice on Monday ordering the protesters out.
"There's been eight confirmed arrests," Dan Sawyer of the Occupy Ottawa legal support committee told The Canadian Press.
"All but one of those people has been released with a $65 trespass ticket."
Mr. Sawyer said the one person who remained in custody may have suffered an injury and was being treated by paramedics.
Police confirmed that eight people were "arrested without incident" and that one person was taken to hospital as a precaution after he complained that a pre-existing injury was aggravated during his arrest.
Mr. Sawyer said there were "probably about a dozen people in the park when police cordoned it off" just after 2 a.m. ET.
Ottawa police Constable Henri Lanctot said earlier that officers were asking protesters to leave the park peacefully.
He said "things are going well ... a number of them have been asked to leave and have done so on their accord."
Const. Lanctot said anyone who had chosen to remain in the park were "subject to being arrested by the police if they don't leave."
Many Ottawa protesters had removed their tents and left on Tuesday, but a handful who were determined to stand their ground remained.