Trudeau had just spoken at the Ronald Reagan Presidential Library and Museum on U.S. Canada relations.
About four miles from the event, a driver turned left in front of the motorcade escorting Trudeau and collided with a CHP motorcycle.
The officer and the woman in the car and her son were all taken to the hospital but their conditions are not yet known.
Trudeau's vehicle was not involved in the crash and the motorcade continued.