The Secular Franciscan Order is an international order of the Catholic Church for laymen, laywomen, and secular clergy (diocesan priests and deacons). It was founded by St. Francis of Assisi in 1209. St. Francis also founded the first Order of friars, for men, and with St. Clare of Assisi, founded the second Order for women. Both the first and second Orders are for men and women who take vows of poverty, chastity and obedience. The members of the Secular Franciscan Order (formerly the Third Order of St. Francis) make a lifetime promise, after a period of formation, to live the Gospel life of Jesus Christ in the manner of St. Francis. For more details, see the various links under this section.
You might notice that the page title doesn't say "SFO". We are now using the initials for the name of our order in Latin - "Ordo Franciscana Seculara" - so that all the Secular Franciscans throughout the world will have the same letters after their name, rather than SFO in the English speaking world and OFS everywhere else.