Banks and Asla, a Norwegian photographer who appeared on Top Model often in the show's 22-season history, named their baby boy York Banks Asla.
"We are so excited for our new baby boy bundle of joy. The journey to now has not been an easy process, as I've shared before. But there was a beautiful bright light at the end of the tunnel for me and his father, Erik," Banks told People in a statement.
"As I gaze into the beautiful eyes of my son, I think about all the people who struggle with fertility or carrying a child and continue to pray for them every day. My hopes and dreams are filled with well wishes that they get to feel what my little treasure, York Banks Asla, feels like in my arms."
Banks revealed in September of last year she had undergone IVF procedures in the hope of conceiving her first child. She and Asla experienced "very traumatic moments" during the process, as Banks was well aware it would be difficult to get pregnant considering her age.
"When I turned 40, the one thing I was not happy about is that I did not have kids. I'm like, 'Damn, the clock is ticking!' Since I was 24, I used to say every year, 'I will have kids in three years...' Because my business is very entrepreneurial, I'm not for hire, so I have to do everything," Banks confessed to the magazine at the time.
"I kept trying to find the time for that to happen. When you're like, 'Okay, I'm just going to do it,' then it's not so easy as you get older."
On Wednesday night, the former supermodel posted a photo of a newborn's hospital hat on Instagram.
"The best present we worked and prayed so hard for is finally here. He's got my fingers and big eyes and his daddy Erik's mouth and chin. As we thank the angel of a woman that carried our miracle baby boy for us, we pray for everyone who struggles to reach this joyous milestone. York Banks Asla, welcome to the world," Banks captioned the image.
Banks has been dating Asla for over two years now but doesn't feel the need to get married. She's publicly voiced how crazy it is for society to find getting married three times the norm in comparison to not walking down the aisle at all.
And the couple is clearly very happy together. One month ago, Banks shared a photo on Instagram with her man, writing, "Everyone deserves to be loved like this."