Jacques Lanctôt (born November 5, 1945, Montreal, Quebec, Canada) was an important member of the violent Quebec separatist group the FLQ.

Lanctôt joined the Front de Libération du Quebec (FLQ) group in 1963 at the age of 17 and was involved in several violent demonstrations in Quebec during the 1960s along with his sister, Louise Lanctôt.

In 1966 a secret eight-page document entitled "Revolutionary Srategy and the Role of the Avant-Garde" was prepared by the FLQ outlining its long-term strategy of successive waves of robberies, violence, bombings and kidnappings, culminating in insurrection and revolution. The goal of the group was to free Quebec from a Canada they viewed as oppressive and capitalistic. Like most of the FLQ Lanctôt was an avowed Marxist.

In 1968, Lanctôt, a member of the FLQ's Liberation cell, met Paul Rose, leader of the Chénier Cell .

As a member of the Liberation Cell of the FLQ he was partners with:

• Jacques Cossette-Trudel
• Louise Lanctôt (Mrs. Louise Cossette-Trudel)
• Marc Carbonneau
• Yves Langlois (aka Pierre Seguin)
• Nigel Barry Hamer (his participation discovered in 1980)

Lanctôt was involved in the kidnapping of the British High Commissioner, James Richard Cross, on October 5, 1970, sparking the October Crisis. Lanctôt and his group held James Cross hostage, taking his photo and sending it to police with a list of demands that included money and the release of other convicted FLQ members. The Liberation Cell advised authorities that Cross will be executed and further threats to Cross' life were delivered to several radio stations along with the FLQ demands. On October 10, their counterparts in the Chénier Cell kidnapped the Quebec Government's Labour Minister, Pierre Laporte, who shortly thereafter was found strangled to death and stuffed in the trunk of a car.

On December 3, 1970, Lanctôt and the four other known FLQ members who had kidnapped James Cross negotiated his release in exchange for a flight to Cuba. Cross was unharmed and reported being well treated by his captors. Later, he secretly left Cuba and went to live in Paris, France.

Jacques Lanctôt returned from exile in Paris on January 11, 1979. He was arraigned in Court and released on bail pending his trial. He was also charged with the February 1970 conspiracy to kidnap Moshe Golem , the Israeli trade commissioner to Canada. He was sentenced to one year in jail for these crimes.

After serving his sentence he reentered Quebec society and became a successful book publisher.