From Streatham train to London St. Pancras, train to Luton Airport Parkway Rail Station, then line 888 bus to Airport Bus Station. 1hrs 19min £22. From Streatham Hill, Leigham Ct Rd Streatham Hill bus to Mayfair, Marble Arch (W1) then bus to Airport Bus Station. 1hrs 45min £10. From Streatham taxi to London Luton. 54min £120. From Streatham drive to London Luton. 54min £8. From Streatham Uber to London Luton. 54min £125.