Okla. Stat. tit. 5, § 5-1: Persons disqualified to practice law – Alien eligibility

No person shall practice as an attorney and counselor at law in

any court of this state who is not a citizen of the United States,

or who holds a commission as judge of any court of record, or who is

a sheriff or coroner; nor shall the clerk of the Supreme Court, or

the clerk of the district court, or probate court, or the deputy of

either, practice in the particular court of which he is clerk or

deputy clerk; but nothing herein contained shall prevent any judge

of any of the courts of this state from finishing any business by

him undertaken in the district, circuit, or Supreme Court of the

United States, prior to his election or appointment as judge; and an

alien who has declared his intention to become a citizen of the

United States may practice as if he were a citizen.