Short answer. Yes. A minor who is legally allowed to marry may also execute marriage settlements, but the agreement is only valid if the persons the law requires to consent to that marriage are also made parties to the settlement itself, not just to the marriage.
What the law says
A minor who according to law may contract marriage may also execute his or her marriage settlements, but they shall be valid only if the persons designated in Article 14 to give consent to the marriage are made parties to the agreement
Family Code, Article 78 — Marriage Settlements Executed by a Minor. Read the full provision →
The general rule: signing the marriage settlement follows signing the marriage
The law treats the capacity to marry and the capacity to sign a prenuptial agreement as tied together. If a minor is legally allowed to marry, that same minor is allowed to execute a marriage settlement — the formal agreement that sets the property rules the couple will live under once married. The minor does not need a guardian to sign on their behalf; they sign it themselves, in their own right, alongside their intended spouse.
The condition that makes it valid
That capacity comes with a condition attached, not a blank check. The settlement is only valid "if the persons designated in Article 14 to give consent to the marriage are made parties to the agreement." In other words, whoever the law requires to consent to the marriage itself must also sign onto the marriage settlement. A settlement the minor signs alone, without those required parties joining in, does not satisfy this article.
Why the extra party matters
Requiring the consenting party to also join the settlement is not a formality for its own sake. A marriage settlement fixes the property regime the couple will be bound by, sometimes for the rest of the marriage, and it can affect what a minor spouse brings into or takes out of the relationship. Making the consenting party a signatory to the settlement itself, not merely a signatory to the marriage license process, gives that safeguard real teeth over the financial terms, not just over whether the wedding happens at all.
This provision does not stand alone
Article 78 expressly makes this rule "subject to the provisions of Title IX of this Code," the part of the Family Code dealing with parental authority. That cross-reference is a signal that a minor's capacity to execute marriage settlements does not exist in isolation from the broader rules on parental authority over a minor's property and civil acts. If your situation involves a minor spouse and property questions beyond the settlement itself, do not assume Article 78 is the only provision in play.