Having represented Leeds South since 1885, Playfair left the House of Commons in 1892 and was ennobled as Baron Playfair, of St Andrews in the County of Fife. He served as a Lord in Waiting (government whip in the House of Lords) under Gladstone and then Lord Rosebery between 1892 and 1895. He was further honoured when he was made a Knight Grand Cross of the Order of the Bath in 1895 and awarded the Harben Gold Medal from the Royal Institute of Public Health in 1897. Playfair is also remembered for promoting a new cipher system invented by Charles Wheatstone, now known as the Playfair cipher.