What type of shoes did Steve McQueen wear in Bullitt?

They are TOD'S Driving Shoes.

"Tod's Driving Shoe. Introduced on shoes made for Fiat magnate Gianni Agnelli. Diego Della Valle's signature pedal grippers altered the footprints of die-hard drivers and became a symbol of casual chic"

Color: brown. Materials: suede leather. Model Sole: Driver. 100% premium Leather. Made in Italy by J.P. Tod's.

If you would like to order these shoes, that retail for 450 dollars, click HERE.

NOTE: He also wore Italian dress shoes in BULLITT, but the brand is unknown.

(Thanks to Michael Langner for the answer, quote, and link!)