Can a deportee from US get a visa to UK?

They can certainly APPLY for one, but whether they'd get it depends upon what they'd been deported from the US for. If it was for suspected involvement in terrorism, involvement in organised crime or the drugs trade, or anything that could pose a danger to the public, then they probably would have their application refused.

If, however, it was for being an illegal immigrant to the US an asylum seeker, or for something like financial fraud or buisness crime which they had already been penalised for, then they'd have a better chance of their application being considered.