Short answer. Generally no. A limited partner, a contributor who is not a general partner, is not a proper party to a lawsuit brought by or against the partnership. The exception is where the very object of the case is to enforce a limited partner's own right against, or liability to, the partnership.
What the law says
A contributor, unless he is a general partner, is not a proper party to proceedings by or against a partnership, except where the object is to enforce a limited partner's right against or liability to the partnership.
Civil Code, Article 1866 — Contributor Not a Proper Party. Read the full provision →
The default: a limited partner stays out of the suit
The Civil Code treats a limited partner very differently from a general partner when it comes to litigation. It provides that a contributor, unless he is a general partner, is not a proper party to proceedings by or against a partnership. A limited partner is such a contributor. So if the partnership is suing an outsider, or is being sued, the limited partner is generally not someone who should be named as a plaintiff or a defendant in that case. The dispute is the partnership's, carried on through those who run it, and the passive investor is ordinarily left off the pleadings entirely.
The reason behind the rule
This flows from what a limited partner is. Their role is to contribute capital and share in profits, not to manage the business or expose themselves the way a general partner does. Because they do not run the firm and their liability is confined to what they put in, dragging them personally into every suit involving the partnership would serve little purpose and would blur the very line that makes limited partnership attractive. The law therefore keeps the ordinary litigation about the business between the partnership and the outside world, rather than routing it through each individual investor.
When a limited partner is a proper party
The rule has a defined exception, and it is about the limited partner's own stake, not the partnership's external dealings. The article allows the limited partner to be a party where the object is to enforce a limited partner's right against or liability to the partnership. So if the dispute is precisely about what the limited partner is owed by the partnership, such as a share of profits or the return of a contribution, or about what the limited partner owes it, then the limited partner properly belongs in the case. What draws them in is a controversy over their personal rights or obligations toward the firm.
What this means if you are named
If you are a limited partner and find yourself named in a suit that is really about the partnership's dealings with an outsider, this article may be a reason you do not belong in it, and that is worth raising early. Conversely, if the case is about your own contribution or your entitlement from the firm, expect that you can properly be included. Because the line turns on what the case is truly about, the pleadings and the relief sought have to be read carefully. A lawyer can assess whether you are a proper party or should be dropped from the case.