From Slough Bus Station line 3 bus to Uxbridge Underground Station then Tube to Harrow-on-the-Hill Underground Station. 54 min £7. From Slough Town Centre, Queensmere Centre (Queensmere Shopping Ctr) line 81 bus to Harlington Corner then line 140 bus to Harrow, St Georges Centre. 1 h 26 min £5. From Slough taxi to Harrow on the Hill. 22 min £66. From Slough drive to Harrow on the Hill. 22 min £3.