Jacqueline Lefebvre was 42 when she disappeared from her family cottage in Mascouche, Quebec, on August 30, 1968. Official records list the Mascouche cottage as the last place she was known to have been seen; after that day she was never heard from again and no verified sighting or destination has been documented.

At the time she vanished Jacqueline was about 5 feet 5 inches tall, weighed about 174 pounds, and was described as having a heavy build with a light or fair complexion, wavy blonde hair and greenish-blue eyes. Investigators recorded identifying details including braces on her teeth, a vertical scar on her abdomen, a hysterectomy scar and a gold wedding band. There is no publicly identified vehicle, note, suspect, or confirmed evidence that a crime occurred.

Her disappearance remains listed in Canadian missing-person records and is associated with the Mascouche Public Security Service reference MSC-180410-011. If anyone has information about Jacqueline Lefebvre or recalls anything from that day at the Mascouche cottage, please share it with local authorities, Crime Stoppers or the National Centre for Missing Persons and Unidentified Remains.