Short answer. Generally yes. Children conceived and born outside a valid marriage are illegitimate, but the law itself flags that this is a default rule, not an absolute one — it applies unless another provision of the Family Code says otherwise for your specific circumstances.

What the law says

Children conceived and born outside a valid marriage are illegitimate, unless otherwise provided in this Code.

Family Code, Article 165 — Who Is an Illegitimate Child. Read the full provision →

Both conception and birth outside marriage matter

The article's wording is precise: children conceived and born outside a valid marriage are illegitimate. It ties illegitimacy to both events — conception and birth — happening outside a valid marriage, not just one or the other. This is the general classification rule the Family Code uses to sort children into legitimate or illegitimate status, and it is the starting point for a wide range of other rights and obligations that depend on that status, such as surname, support, and inheritance.

What "a valid marriage" is doing in this sentence

The rule specifically requires a valid marriage, not simply the appearance of one. If there is any question about whether a marriage between the parents was itself valid — as opposed to void or otherwise defective — that question can affect how a child's status is classified under this article, since the article's protection runs only to children conceived and born within a marriage that actually holds up as valid.

The article itself says this is not the final word

The sentence ends with an important qualifier: "unless otherwise provided in this Code." The Family Code itself signals that this general rule has exceptions elsewhere within the same code. This article does not identify what those exceptions are, so anyone whose situation might fall into one of them should not assume this general default automatically applies to them without checking the specific provision that might change the outcome.

Why this classification matters beyond the label itself

Whether a child is classified as legitimate or illegitimate under this article is not merely a label — it is the threshold question that other parts of the Family Code build on, covering matters like which surname the child carries, how support obligations are structured, and how the child inherits. If you are trying to understand what follows from your child's status, this article is where that status gets determined, but the practical consequences flow from separate provisions built on top of it.

Cases citing this provision

These Supreme Court decisions cite the provision above. We list them so you can read them yourself; the summaries of what each decided are not ours to give.

Related provisions

Note. Statute text quoted on this page is reproduced from the official enactment and is linked to the full provision. The explanation around it is general legal information from Vivas & Nobles Law Office, not legal advice. Whether it applies to your situation depends on facts only a lawyer reviewing them can assess.