In a statement, Toronto's fugitive squad said it had arrested Const. Witney Hutchinson in Ajax just east of the city.
Hutchinson, 28, is wanted for a murder in Jamaica.
Authorities there are investigating the killing of as many as 40 civilians by officers of the Jamaica Constabulary Force.
Police allege the constable fled Jamaica after the murder of Sylvester Gallimore in May 2011, and entered Canada legally to visit family.
RCMP had asked Toronto police to arrest him. The arrest was effected Friday and Hutchinson was being held pending his removal from Canada, police said.
Previously charged in the Gallimore killing was Det. Cpl. Kevin Adams, who is also accused in the death of three other men in the parish of Clarendon.
The Independent Commission of Investigations in Jamaica has been investigating deaths first thought to have been the result of civilian violence, but later discovered to have been the work of police officers.
In April, the commission cited cases in which nine civilians were killed in Clarendon in shootings initially believed to have been carried out by civilian gunmen. One man was shot dead in hospital, where he was recovering from an initial attempt on his life.
In all, 11 officers from the Clarendon police division, including Hutchinson, were charged with murder earlier this year.
The commission has refused to confirm the existence of police death squads, but has instead referred to officers under investigation for "unlawful killings" between 2009 and 2013. It has also been looking into whether superiors ordered subordinate officers to carry out the killings.
In April, a coalition of Jamaican lobby groups said they had reported to the Inter-American Commission on Human Rights claims that "death squads" within the Jamaica Constabulary Force were engaging in extrajudicial killings.
The claims surfaced in January when a retired senior police officer told the Sunday Gleaner newspaper about special teams ordered by senior officers to kill suspected criminals. Police brass strenuously denied the allegation.
Last year, Jamaica's security forces were involved in the deaths of 258 civilians — the vast majority were shot dead.
Terrence Williams, head of the commission, did not immediately return calls seeking comment.