Conn. Gen. Stat. § 46b-20a: Eligibility to marry.

A person is eligible to marry if such person is:

(1) Not a party to another marriage, or a relationship that provides substantially the same rights, benefits and responsibilities as a marriage, entered into in this state or another state or jurisdiction, unless the parties to the marriage will be the same as the parties to such other relationship;

(2) At least eighteen years of age;

(3) Except as provided in section 46b-29, not under the supervision or control of a conservator; and

(4) Not prohibited from entering into a marriage pursuant to section 46b-21 or 46b-21a.