Nope. Frontosa are very aggressive toward the females and you need to keep them in a harem or colony. At least a 120 gallon tank is required for a small group. Technically you can keep a single male in a 55, but it'll be one boring tank.
They're both big, and they're both cichlids, but their behavior patterns are entire different so it's not a good idea. Choose either African or New world, they make a terrible mix.
I have both an oscar and a frontosa and both of them are doing great together! they both hang out and do not disturb either or. Both my frontosa and my oscar are approximately 8 inchs so they are closer to the adult stage. So my opinion would be that it would be ok depending on the temperments of your fish. I knew that my oscar isnt a terror and when i got my frontosa i watched him within the tank with others and hes was not a terror either and looked healthy as can be so i picked him up and everything has been great since!! =) GOOD LUCK!!