Opus Dei is an organization founded in Spain in 1928 by Josemaria Escriva de Balaguer. The stated aim of Opus Dei is to "spread throughout society a profound awareness of the universal call to holiness and apostolate through one's professional work carried out with freedom and personal responsibility." Opus Dei is made up of lay members and priests; Opus Dei laity continue to work in the secular world, but remain under the strict spiritual direction of Opus Dei. All Opus Dei members follow "the plan of life," made up of spiritual practices such as daily Mass, rosary, spiritual reading, and mental prayer, as well as Opus Dei prayers and customs. Despite its seemingly noble intentions, Opus Dei has stirred up controversy in countries all over the world. Families of Opus Dei members are almost never involved in the vocation process, (in fact Opus Dei itself often discourages its new members from even telling their families about their decision!) Also questionable are Opus Dei's recruiting tactics, which are comparable to the tactics used by cultic groups. So there you have it, not sure what is in "The Da Vinci Code" but you should be able to compare them for yourself.

A secret -luciferian- society part of the Roman Catholic Church. My 2 cents.

No relation However the current group is a continuation of another. The older group was only called it - it was not the official name. I believe it was a group of priests, but, I could be mistaken.