| Season 4 | 2017-18 | 8.0/10 | ||
| 1 | The Flash Reborn |
 |
7.6 | |
| 2 | Mixed Signals |
|
7.0 | |
| 3 | Luck Be a Lady |
|
7.6 | |
| 4 | Elongated Journey Into Night |
|
8.0 | |
| 5 | Girls Night Out |
|
6.5 | |
| 6 | When Harry Met Harry... |
|
7.0 | |
| 7 | Therefore I Am |
|
7.0 | |
| 8 | Crisis on Earth-X, Part 3 |
 |
9.0 | |
| 9 | Don't Run |
|
8.3 | |
| 10 | The Trial of The Flash |
|
8.2 | |
| 11 | The Elongated Knight Rises |
|
7.3 | |
| 12 | Honey, I Shrunk Team Flash |
|
7.6 | |
| 13 | True Colors |
|
8.2 | |
| 14 | Subject 9 |
|
8.3 | |
| 15 | Enter Flashtime |
|
8.7 | |
| 16 | Run, Iris, Run |
|
6.8 | |
| 17 | Null and Annoyed |
 |
6.0 | |
| 18 | Lose Yourself |
|
9.5 | |
| 19 | Fury Rogue |
|
7.3 | |
| 20 | Therefore She Is |
|
6.8 | |
| 21 | Harry and the Harrisons |
|
6.0 | |
| 22 | Think Fast |
|
7.8 | |
| 23 | We Are the Flash |
|
8.0 |