Ora has already shot campaign photos for the label, run by Madonna and her daughter Lourdes, reported Sun online.
"Lourdes has been a fan of Rita for a while and has been to many of her gigs. She persuaded her mum to see her. They met at the Met Ball in New York last week and Madonna admired Rita's attitude so signed the idea off," a source said.
"Rita jumped at the chance because she's a huge fan of Madonna. She also hopes it gets a break in the States the same way she got in UK," the source added.
The designer stores located in the US offer collection inspired from the 1980s style and targets teenagers.