In technical heraldic language the coat of arms of Archbishop Roussin is described as: Azure a Cross of the Society of Mary Argent in base two ears of wheat Or. The arms are placed on a patriarchal cross Or ensigned by the green clerical hat of a Roman Catholic Archbishop. The motto is: FORTES IN FIDE ("Steadfast in Faith").

The cross in the shield is the insignia of the Society of Mary of which Archbishop Roussin is a member. As a Marianist, he taught for many years and served as Provincial Superior of the Order from 1980-1986. The cross reflects the Marian spirituality of the Order. Christ comes to us through Mary, Mary forms Christ and continues to do so in us today. Blue, the colour of the field of the arms, is a colour traditionally associated with Mary.

The sheaves of wheat symbolize Archbishop Roussin's prairie roots. The sheaves also allude to the image of the grain of wheat which must fall to the ground and die to bring forth new life. As well, they represent the Bread of Life, the Eucharist.

Behind the shield is the gold metropolitan cross, indicating that Archbishop Roussin heads a metropolitan see (an archdiocese). The green ecclesiastical hat or "gallero" has ten tassels on each side, an indication of the rank of archbishop. Both symbols are the distinctive heraldic emblems of an archbishop in the Latin Rite of the Catholic Church.

Archbishop Roussin has chosen the motto Fortes in Fide (Steadfast in Faith), as something said of those whose lives are deeply rooted in the person of Christ.

After his installation, the Archbishop's personal coat of arms will be impaled, meaning that it will be joined to the arms of the Archdiocese of Vancouver. This heraldic convention places side by side the symbols of the two coats of arms, with Archbishop Roussin's arms compressed in the left half of the shield (the viewer's right), and the archdiocesan arms in the right half (the viewer's left).

The coat of arms was granted to Archbishop Roussin by the Chief Herald of Canada from the Canadian Heraldic Authority in the Chancellery of Honours by letters patent dated February 16, 2004.

Gordon Macpherson, Niagara Herald Extraordinary, painted the arms of Archbishop Roussin.