The 22-year-old model – whose father is dancer Jimmy Gulzar – has been signed up to front the supermarket's latest fashion collection.
Phoenix said: "I feel incredibly privileged to be able to represent George at Asda. I loved the creativity of the shoot and working out how to put the outfits together."
She added: "My favourite piece from the collection has to be the boots! They are so versatile, whether you’re wearing them with a dress, a pair of jeans or even sweatpants.”
Watch: Mel B joins The Fashion Hero as new host
Mel B tweeted she is "Soooo proud!!!"
Phoenix is fronting George's new G21 collection which is aimed at Generation Z.
The model is the eldest daughter of 'Scary Spice' Mel B.
The Spice Girl is also mum to Angel, 13, from her relationship with actor Eddie Murphy, and Madison, nine, from her marriage to film producer Stephen Belafonte.
Mel B's marriage to Belafonte ended in a difficult divorce in 2017, and the singer has spoken out about the domestic violence she suffered.
Phoenix has also opened up about what it is like to be a child in a family that suffers domestic violence.
She wrote on Instagram in 2019: "My life as a kid was so happy. And then, when I was eight a guy came along and everything changed. I didn’t like him but he made my mum happy. And then he didn’t.
"I can remember when I started standing outside her bedroom listening to her sobbing. I didn’t know what to do. I knew that things I heard and things I saw were wrong but I said anything nothing, it would make it worse. I’d tried once and because of that, because of me, I never saw my granddad again until he was on his deathbed nearly ten years later. I blamed myself for messing up and for being helpless but I know now it wasn’t my fault.
"Domestic violence, domestic abuse is never our fault. We are just kids. All we can do - all I did - was hope and prayed it would end, that he would go and I would always be there for my mum and my sister and that has happened. It can happen. Life is better now but we are all still healing."
Watch: Mel B on why she thinks she was booted off The Masked Singer