The airline said Flight 802 slide off a runway at Pierre Elliott Trudeau International Airport after landing shortly before 8 p.m. Montreal time. The plane was apparently rolling along the runway at a slow speed when the incident occurred.
The 105 passengers and six crew members aboard were evacuated from the Boeing 737 by the stairs and were bused to the terminal.
American Airlines said no one was injured and the plane doesn't appear to be damaged.
Flight 802 departed from Dallas/Fort Worth International Airport earlier Tuesday.
The Federal Aviation Administration said the weather in Montreal was bad, with high winds and rain. The airline said it is did not want to speculate yet on the cause and will investigate the incident.
The Federal Transportation Safety Board said it will launch an investigation.