From Heathrow Terminals 1-3 train to Paddington Underground Station, Tube to London Euston, then train to Northampton. 1hrs 42min £50. From Heathrow Central Bus Station line 724 bus to Watford Junction then train to Northampton. 2hrs 15min £27. From Heathrow Airport London bus to Northampton. 2hrs 25min £45. From Heathrow Central Bus Station line 707 bus to Delapre Crescent. 2hrs 25min £17. From London Heathrow Airport (LHR) drive to Northampton. 1hrs 10min £16.