Okla. Const. art. XXIII, § 1A

A. As used in this section, "labor organization" means any organization of any kind, or agency or employee representation committee or union, that exists for the purpose, in whole or in part, of dealing with employers concerning wages, rates of pay, hours of work, other conditions of employment, or other forms of compensation.

B. No person shall be required, as a condition of employment or continuation of employment, to:

1. Resign or refrain from voluntary membership in, voluntary affiliation with, or voluntary financial support of a labor organization;

2. Become or remain a member of a labor organization;

3. Pay any dues, fees, assessments, or other charges of any kind or amount to a labor organization;

4. Pay to any charity or other third party, in lieu of such payments, any amount equivalent to or pro rata portion of dues, fees, assessments, or other charges regularly required of members of a labor organization; or

5. Be recommended, approved, referred, or cleared by or through a labor organization.

C. It shall be unlawful to deduct from the wages, earnings, or compensation of an employee any union dues, fees, assessments, or other charges to be held for, transferred to, or paid over to a labor organization unless the employee has first authorized such deduction.

D. The provisions of this section shall apply to all employment contracts entered into after the effective date of this section and shall apply to any renewal or extension of any existing contract.

E. Any person who directly or indirectly violates any provision of this section shall be guilty of a misdemeanor.