As we reported, Vivian said her reason for the change is "the fact that I no longer live with or wish to be related to my biological father in any way, shape or form."
Back in December 2020, Elon tweeted his support for the transgender community, but added ... "All these pronouns are an esthetic nightmare."
It's unclear what's at the root of Vivian's desire to part ways with her father -- seems like it must be more than just that tweet.
In any event, Elon's ex-wife Justine Wilson posted about being proud of Vivian as the news broke about her legal request. Neither Mom or daughter has said anything publicly about Elon yet, but Vivian's gotta be over the moon now that it's all official.