The Oklahoma Statues Title 43 tell us who may be a wedding officiant in Oklahoma.
A. All marriages must be contracted by a formal ceremony performed or solemnized in the presence of at least two adult, competent persons as witnesses, by a judge or retired judge of any court in this state, or an ordained or authorized preacher or minister of the Gospel, priest or other ecclesiastical dignitary of any denomination who has been duly ordained or authorized by the church to which he or she belongs to preach the Gospel, or a rabbi and who is at least eighteen (18) years of age.
B. 1. The judge shall place his or her order of appointment on file with the office of the court clerk of the county in which he or she resides.
2. The preacher, minister, priest, rabbi, or ecclesiastical dignitary who is a resident of this state shall have filed, in the office of the court clerk of the county in which he or she resides, a copy of the credentials or authority from his or her church or synagogue authorizing him or her to solemnize marriages.
3. The preacher, minister, priest, rabbi, or ecclesiastical dignitary who is not a resident of this state, but has complied with the laws of the state of which he or she is a resident, shall have filed once, in the office of the court clerk of the county in which he or she intends to perform or solemnize a marriage, a copy of the credentials or authority from his or her church or synagogue authorizing him or her to solemnize marriages.
4. The filing by resident or nonresident preachers, ministers, priests, rabbis, ecclesiastical dignitaries or judges shall be effective in and for all counties of this state; provided, no fee shall be charged for such recording.
C. No person herein authorized to perform or solemnize a marriage ceremony shall do so unless the license issued therefor be first delivered into his or her possession nor unless he or she has good reason to believe the persons presenting themselves before him or her for marriage are the identical persons named in the license, and for whose marriage the same was issued, and that there is no legal objection or impediment to such marriage.
D. Marriages between persons belonging to the society called Friends, or Quakers, the spiritual assembly of the Baha’is, or the Church of Jesus Christ of Latter Day Saints, which have no ordained minister, may be solemnized by the persons and in the manner prescribed by and practiced in any such society, church, or assembly.
The above information is taken from the Oklahoma Statues Title 43 Marriage http://www.oscn.net/applications/oscn/DeliverDocument.asp?CiteID=71793