She and husband Brad Bratcher welcomed baby daughter Gray Audrey into the world on Monday, May 21, People reports.
The actress is best known for having played the bubbly Six LeMeure on Blossom, but has also starred in The Parkers and lent her voice to Family Guy.
She told People: "Brad and I are, of course, ecstatic she's here and we are madly in love with her already. It's truly unimaginable how quickly she wrapped us around her little finger!
"We are exhausted, but enjoying every moment of it, as every moment she's doing something new and memorable."
Describing her new family member, von Oÿ said: "She has an incredible amount of hair! So much so, that the hospital nurses washed it, brushed it, and put a bow in it on the first day! We know kids a year old who don't have half the amount of hair our daughter had at birth!"
Watch a scene from Blossom featuring Jenna von Oÿ below: