| Wimbledon | 07/02 16:00 | 23 | Ryan Harrison v Roberto Carballes Baena | 6-1,6-4,6-2 | |
| ATP Eastbourne | 06/25 12:40 | 25 | [223] Jay Clarke v Ryan Harrison [58] | 6-4,6-1 | |
| ATP Queens | 06/19 17:45 | 25 | [58] Ryan Harrison v Kyle Edmund [17] | 6-7,4-6 | |
| French Open | 05/29 09:00 | 23 | [56] Ryan Harrison v Maximilian Marterer [70] | 1-6,3-6,5-7 | |
| ATP Geneva | 05/21 16:00 | 25 | [61] Frances Tiafoe v Ryan Harrison [56] | 3-6,7-6,6-4 | |
| ATP Rome | 05/15 20:25 | 25 | [57] Ryan Harrison v Marin Cilic [5] | 7-6,1-6,6-7 | |
| ATP Rome | 05/13 12:40 | 24 | [59] Ryan Harrison v Yuichi Sugita [46] | 7-6,6-3 | |
| ATP Madrid | 05/09 14:25 | 25 | [9] John Isner v Ryan Harrison [59] | 7-6,7-6 | |
| ATP Madrid | 05/08 16:15 | 24 | [69] Guillermo Garcia-Lopez v Ryan Harrison [59] | 4-6,6-7 | |
| ATP Houston | 04/12 18:35 | 26 | [72] Taylor Fritz v Ryan Harrison [54] | 3-6,6-0,6-3 | |
| ATP Houston | 04/10 20:35 | 25 | [187] Miomir Kecmanovic v Ryan Harrison [54] | 4-6,3-6 | |
| Davis Cup | 04/08 19:00 | 27 | [54] Ryan Harrison v Ruben Bemelmans [110] | 6-3,6-4 | |
| ATP Miami | 03/21 15:00 | 23 | [53] Ryan Harrison v Joao Sousa [80] | 6-7,6-7 | |
| ATP Indian Wells | 03/09 01:05 | 23 | Ryan Harrison v Federico Delbonis | 2-6,6-4,5-7 | |
| ATP Acapulco | 03/01 23:30 | 27 | Ryan Harrison v Alexander Zverev | 4-6,1-6 | |
| ATP Acapulco | 02/28 23:30 | 26 | Ryan Harrison v Diego Schwartzman | 6-3,5-7,6-4 | |
| ATP Acapulco | 02/27 01:00 | 25 | John Isner v Ryan Harrison | 3-6,6-7 | |
| ATP Delray Beach | 02/20 16:00 | 25 | Reilly Opelka v Ryan Harrison | 7-6,7-6 | |
| ATP New York | 02/15 20:00 | 26 | Ryan Harrison v Ivo Karlovic | 4-6,4-6 | |
| ATP New York | 02/13 00:30 | 25 | Ryan Harrison v Donald Young | 6-3,7-6 | |
| Australian Open | 01/19 09:00 | 25 | Ryan Harrison v Marin Cilic | 6-7,3-6,6-7 | |
| Australian Open | 01/17 04:15 | 24 | Pablo Cuevas v Ryan Harrison | 4-6,6-7,4-6 | |
| Australian Open | 01/15 00:00 | 23 | Dudi Sela v Ryan Harrison | 3-6,7-5,6-3,5-7,2-6 | |
| ATP Auckland | 01/09 00:50 | 25 | Steve Johnson v Ryan Harrison | Cancelled | |
| ATP Brisbane | 01/07 09:00 | 29 | Nick Kyrgios v Ryan Harrison | 6-4,6-2 | |
| ATP Brisbane | 01/06 03:20 | 28 | Alex De Minaur v Ryan Harrison | 6-4,6-7,4-6 | |
| ATP Brisbane | 01/05 04:20 | 27 | Denis Istomin v Ryan Harrison | Retired | |
| ATP Brisbane | 01/04 05:15 | 26 | Ryan Harrison v Yannick Hanfmann | 6-7,6-4,6-2 | |
| ATP Brisbane | 01/04 00:00 | 26 | Ryan Harrison v Andy Murray | Cancelled | |
| ATP Brisbane | 01/01 01:00 | 25 | Ryan Harrison v Leonardo Mayer | 6-4,3-6,6-2 |