Family Code §400. 
Marriage may be solemnized by any of the following who is of the age of 18 years or older:
   (a) A priest, minister, or rabbi of any religious denomination.
   (b) A judge or retired judge, commissioner of civil marriages or retired commissioner of civil marriages, commissioner or retired commissioner, or assistant commissioner of a court of record in this state.
   (c) A judge or magistrate who has resigned from office.
   (d) Any of the following judges or magistrates of the United States:
   (1) A justice or retired justice of the United States Supreme Court.
   (2) A judge or retired judge of a court of appeals, a district court, or a court created by an act of Congress the judges of which are entitled to hold office during good behavior.
   (3) A judge or retired judge of a bankruptcy court or a tax court.
   (4) A United States magistrate or retired magistrate.
   (e) A legislator or constitutional officer of this state or a member of Congress who represents a district within this state, while that person holds office.

§ 401. 
(a) For each county, the county clerk is designated as a commissioner of civil marriages.
(b) The commissioner of civil marriages may appoint deputy commissioners of civil marriages who may solemnize marriages under the direction of the commissioner of civil marriages and shall perform other duties directed by the commissioner.

§ 402.  In addition to the persons permitted to solemnize marriages under Section 400, a county may license officials of a nonprofit religious institution, whose articles of incorporation are registered with the Secretary of State, to solemnize the marriages of persons who are affiliated with or are members of the religious institution.  The licensee shall possess the degree of doctor of philosophy and must perform religious services or rites for the institution on a regular basis.  The marriages shall be performed without fee to the parties.