Kilner's bowling had greater success in 1921, helping Yorkshire to rise to third in the Championship. Used more regularly, he took 61 wickets (average 18.80), including his first five-wicket hauls in an innings]], against Warwickshire and Nottinghamshire. He scored 1,137 runs at an average of 27.73. He made centuries in the two matches against Northamptonshire, sharing big partnerships in both games: 276 with Rhodes in the first and 299 with Percy Holmes in the second. His overall performance left him sixth in the Yorkshire batting averages, and fourth in the bowling averages. Through the winter, he continued to develop his bowling.