CrossCountry operates a train from Uxbridge to Southampton hourly. Tickets cost $40 - $60 and the journey takes 50 min. Alternatively, National Express operates a bus from Uxbridge to Southampton every 3 hours. Tickets cost $24 - $29 and the journey takes 2 h 15 min.
How to get from Uxbridge to Southampton
From West Drayton train to Reading then train to Southampton Central. 1 h 58 min £47. From Uxbridge, Crown Walk bus to Heathrow Airport London, bus to Woking, then train to Southampton Central. 3 h 34 min £26. From Uxbridge, Belmont Road bus to Heathrow Central Bus Station then bus to Southampton City Centre, Coach Station. 3 h 35 min £23. From Uxbridge drive to Southampton. 1 h 13 min £13.