When is it okay to start dating after a divorce?
There is no right interval, and nobody can tell you when you are ready. What can be said clearly is that dating before the divorce is final carries consequences that dating afterward does not, and that if you have children the question of when they meet someone is separate from when you start.
Those two distinctions do more work than any rule about waiting a year.
Before the case is final
Legally, in most states, this will not change the outcome. Every state offers a no-fault route, and a new relationship rarely affects property division on its own.
Practically it can complicate things considerably.
It raises the temperature, reliably. A negotiation that was going reasonably can stop, and cases settle far more cheaply when both people are calm. This is the most common real cost.
Money spent can matter. Marital funds spent on a new relationship can be raised as dissipation, and it is the kind of detail that gets found and does not read well.
It can complicate parenting discussions, particularly if children have met someone before anyone agreed they would.
In most states, conduct can still be weighed in spousal support, and in a few it is decisive. South Carolina bars alimony outright for adultery committed before the settlement agreement is signed; North Carolina makes it mandatory in both directions for conduct before the date of separation, denying support to a dependent spouse who strayed and awarding it against a supporting spouse who did. Two things undo that mandate in North Carolina, and nobody should give up on support without checking them: if both spouses did it, the judge gets discretion back, and conduct the other spouse forgave, for instance by resuming the marriage after finding out, cannot be counted at all. Fewer states weigh conduct when dividing property. The cutoff date matters as much as the rule: some states stop counting at separation, others not until a settlement is signed. Find out which kind of state you are in before assuming this is irrelevant.
None of that means do not. It means the timing has a cost attached, and it is worth choosing knowingly rather than discovering it.
Whenever you start, be deliberate about the children
This is where the real damage happens, and it happens with good intentions.
Wait longer than feels necessary before introductions. Children have already had one adult relationship reorganize their lives without their input. A parade of people who then leave repeats that.
Agree it with your co-parent if you can, and check your parenting plan, since many include a provision on exactly this. If yours does not and you are still drafting, it belongs in there while the question is still hypothetical. What goes in a parenting plan covers it.
Do not ask them to keep it secret. It puts a child in the middle of the adults, which is the one thing that does lasting harm regardless of everything else.
Expect complicated reactions, including from children who seemed fine. Liking someone can feel to a child like betraying the other parent.
The question worth asking instead of "how long"
Not how much time has passed, but:
Can you talk about your marriage without it taking over the evening? Are you looking for company, or for evidence that you are still wanted? Would you be alright if this particular thing ended? Are you introducing someone because they matter, or because you want the household to feel normal again?
Those are more diagnostic than any interval, and they are why the standard advice to wait a year is both roughly reasonable and completely arbitrary.
The thing nobody says
There is no correct grief schedule, and the people around you will have opinions in both directions: that you are moving too fast, or that you should be getting out there. Both are about them.
Some people are ready quickly and it works. Some take years. Some discover a year in that they were not ready at all, which is information rather than failure. Recovery does not run in a straight line, and this is one of the places that shows up most.
Whether conduct during a divorce can affect support or property varies by state. For support, most states do allow it to be weighed, and a few treat adultery as an outright bar. The cutoff date varies too: some states stop counting at separation, others not until a settlement is signed. If your case is still open and this is a live question, it deserves a real conversation with your attorney rather than an assumption.