Comics yes, X-Men, yes, MCU, no. But I asked this question the other day and I’m as disappointed as you lol.

No, not in the MCU

If you’re talking about the MCU, I’m kinda confused why you would even ask as we already known who there father is since Avengers: Age of Ultron and the X-Men haven’t even been introduced in the MCU yet so it’s obviously not Magneto

Magneto could be their biological father, and the Maximoffs just adopted them. However I hope that's not the case, it wouldn't make much sense in the continuity and would create an unnecessary plot

Before they showed their parents in Wandavision, I thought that may have been the case, but since the last episode, I think all hope of that is gone. The memories weren’t faked or anything, and you have pretty solid memories at 10.

It is possible Wanda and Quicksilver both has mutant X-genes since Wanda stopped that Stark bomb from going off as a child. In the X-Men movie universe Magneto didn't even know Quicksilver was his son. So it is possible in the MCU Magneto knows he has twins but the twins don't know their father is Magneto. Or it is possible that none of them knows. Marvel Studios is most likely trying to trick was with Oleg Maximoff. Magneto could be their biological estranged father and Oleg is their stepfather. Maybe their mother somehow cheated on her husband at some point, lol.

As much as I want that to be true, I don’t think it’s likely. Best we’ll probably get, is if the XCU and MCU become one, then maybe we’ll get a scene in a multiverse movie where both universe’s twins meet, and they’re like, “In my world, your dad is Magneto.” Assuming they even know who that is.

In X-Men, yes. We don't know yet in the MCU.

If this IS true, then perhaps wanda's mother divorced and remarried.

BUT it's probably not.

In the comics, the Maximoffs adopt Wanda and Pietro