There is Jolla's Sailfish OS that has been built on Redhat Linux. However, the phone isn't exactly great hardware-wise. A better phone with the same OS is about

There is Jolla's Sailfish OS that has been built on Redhat Linux. However, the phone isn't exactly great hardware-wise. A better phone with the same OS is about to be released later this year by an Indian company (Intex) but I don't know whether it will be available globally.