The suspect, whose name was not released, was in custody and undergoing a psychiatric evaluation ahead of a Monday court appearance, Royal Canadian Mounted Police announced.
Bishop David Monroe was apparently struck with a blunt object Friday night. The Canadian Broadcasting Corp. said he was treated at a hospital for head and neck injuries.
The motive for the alleged assault was not immediately known.
Mounties said they were led to the suspect by a report of a delusional man being brought into a Kamloops hospital by family members. Officers found the man hiding in a shed at his father's home.
"They (relatives) said his mental state was quite deteriorated and he was apparently having some delusions of some sort involving religion," RCMP Staff Sgt. Garry Kerr told the CBC.