In 1971, he co-founded Faith and Light with Marie-Hélène Mathieu, which also works for people with developmental disabilities, their families, and friends in over 80 countries.

In February 2020, an internal report published by L'Arche[4] concluded that Vanier sexually abused six women in Trosly-Breuil, France, between 1970 and 2005.

[7][8] In early 1945, Vanier was visiting Paris, where his father was Canadian ambassador; he and his mother went to assist survivors of Nazi concentration camps.

[11] In 1964, through Vanier's friendship with a priest named Thomas Philippe, he became aware of the plight of thousands of people institutionalized with developmental disabilities.

Vanier invited two men, Raphael Simi and Philippe Seux, to leave the institutions where they resided and live with him in Trosly-Breuil, France.

[23] During one of his lectures, he touched on his distaste for barriers around people with intellectual disabilities, a motivating philosophy behind L'Arche: "We must do what we can to diminish walls, to meet each other.

Writing in the New York Times, critic Ken Jaworowski observed that "just watching the residents leads you to confront and change many of your own preconceptions.

[27] Among those he influenced were the Dutch Catholic priest, professor, writer and theologian Henri Nouwen who came to join the L'Arche Daybreak community in Richmond Hill, Ontario.

[29][30] According to a joint statement by leaders of L'Arche International, Vanier had engaged in "manipulative and emotionally abusive" sexual relationships with six women without disabilities in France, between 1970 and 2005.

The statement read, "These women reported similar facts associated with highly unusual spiritual or mystical explanations used to justify these behaviours...

Vanier was also a member of a small clandestine group which subscribed to and participated in some of the sexual practices of disgraced priest Thomas Philippe, the L'Arche statement said.

[5] A fuller report by an independent group commissioned by L'Arche, published in January 2023, learned of 25 different women who had experienced a sexual act or intimate gesture (such as kissing on the mouth or caresses to the body, most commonly the breasts) with Jean Vanier.

Vanier wrote in May 2015 that he now accepted that Philippe "hurt mature and intelligent people who appear to have placed all their trust in him" and that "I am unable to peacefully reconcile these two realities.

[43] In March 2015, Vanier was awarded the $1.7 million[44] Templeton Prize in recognition of his advocacy for people with disabilities and his contributions to a broader exploration of helping the weak and vulnerable.

[45][16] On September 27, 2016, Vanier received the Peace Abbey Foundation (USA) International Courage of Conscience Award in Trosly-Breuil, France, for his lifelong commitment to building a world of inclusion for individuals with disabilities.

[46] Many schools were previously named after Vanier, however, as of 2022, all of them have been renamed in light of the posthumous report of his involvement in abusive sexual relationships: