8 C.F.R. § 337.1
(a) Form of oath. Except as otherwise provided in the Act and after receiving notice from the district director that such applicant is eligible for naturalization pursuant to § 335.3 of this chapter, an applicant for naturalization shall, before being admitted to citizenship, take in a public ceremony held within the United States the following oath of allegiance, to a copy of which the applicant shall affix his or her signature:
I hereby declare, on oath, that I absolutely and entirely renounce and abjure all allegiance and fidelity to any foreign prince, potentate, state, or sovereignty, of whom or which I have heretofore been a subject or citizen; that I will support and defend the Constitution and laws of the United States of America against all enemies, foreign and domestic; that I will bear true faith and allegiance to the same; that I will bear arms on behalf of the United States when required by the law; that I will perform noncombatant service in the Armed Forces of the United States when required by the law; that I will perform work of national importance under civilian direction when required by the law; and that I take this obligation freely, without any mental reservation or purpose of evasion; so help me God.
(d) Renunciation of title or order of nobility. A petitioner or applicant for naturalization who has borne any hereditary title or has been of any of the orders of nobility in any foreign state shall, in addition to taking the oath of allegiance prescribed in paragraph (a) of this section, make under oath or affirmation in public an express renunciation of such title or order of nobility, in the following form:
[22 FR 9824, Dec. 6, 1957, as amended at 24 FR 2584, Apr. 3, 1959; 32 FR 13756, Oct. 3, 1967; 56 FR 50499, Oct. 7, 1991]