London Heathrow Airport (LHR) to Oxford by Bus
For 26 GBP and a time duration of 80-100 minutes, you can get from LHR to Oxford by bus. National Express and “The Airline” are the bus companies operating buses 24 hours, 7 days a week, every 30 minutes during peak time.
London Heathrow Airport (LHR) to Oxford by Train
You could take the train instead of a bus from Heathrow to Oxford. This is a little more expensive mode of transport, but it is faster. The trip from LHR to Oxford can be via two routes: 1) Take the Heathrow Express train to Paddington and then take another train from there to Oxford; 2) Take a Rail Air bus from Heathrow Central bus station to Reading train station, and from there take a train directly to Oxford.
Private Taxi to Oxford