Though the town has been part of England for centuries, its location near the border meant there was traditionally a strong community of Welsh-speakers, and possesses the only Welsh language bookshop outside the Principality. It's unclear whether the language is still actively spoken, but the controversial perennial League of Wales champions, TNS, are based in the town.
There are certainly some people in Oswestry who are still brought up speaking Welsh fluently. Not sure what use it is to them going about their every day lives though.
(TNS, based in England as you say, are actually the only professional team in the Welsh Premier League).