Okla. Const. art. II, § 12

Officers of United States or other states - Ineligibility to office. No member of Congress from this State, or person holding any office of trust or profit under the laws of any other State, or of the United States, shall hold any office of trust or profit under the laws of this State; provided, neither the provisions of this section nor any other provision of this Constitution or state law shall be construed to prohibit the following officeholders from holding at the same time any other office of trust or profit: 1. Officers and enlisted members of the National Guard; 2. Officers and enlisted members of the National Guard Reserve; 3. Officers of the Officers Reserve Corps of the United States; 4. Enlisted members of the Organized Reserves of the United States; and 5. Officers and enlisted members of the Oklahoma State Guard and any other active militia or military force organized under state law. The Legislature shall have the power to enact laws to further implement the provisions of this section. Amended by State Question No. 769, Legislative Referendum No. 364, adopted at election held on Nov. 4, 2014 (amendment proposed by Laws 2014, S.J.R. No. 33, § 1).