| Career - ERA | |||
| Rk | Player Name | Totals | |
| 1 | Hyun-Jin Ryu | 3.74 | |
| 2 | James Paxton | 4.14 | |
| 3 | Masahiro Tanaka | 4.19 | |
| 4 | R.A. Dickey | 4.50 | |
| 5 | Tyler Anderson | 4.91 | |
| 6 | John Means | 4.94 | |
| 7 | CC Sabathia | 5.96 | |
| Single Season - ERA | |||||
| Rk | Player Name | Totals | Year | ||
| 1 | Hyun-Jin Ryu | 2.45 | 2019 | ||
| 2 | James Paxton | 3.38 | 2015 | ||
| 3 | Masahiro Tanaka | 3.50 | 2015 | ||
| 4 | Masahiro Tanaka | 3.53 | 2017 | ||
| 5 | Masahiro Tanaka | 3.59 | 2016 | ||
| 6 | James Paxton | 3.60 | 2019 | ||
| 7 | Hyun Jin Ryu | 3.62 | 2021 | ||
| 8 | Hyun-Jin Ryu | 3.70 | 2020 | ||
| 9 | John Means | 3.76 | 2022 | ||
| 10 | James Paxton | 3.77 | 2016 | ||
| 11 | Hyun Jin Ryu | 4.07 | 2022 | ||
| 12 | Felix Hernandez | 4.13 | 2017 | ||
| 13 | Alex Cobb | 4.14 | 2022 | ||
| 14 | R.A. Dickey | 4.24 | 2016 | ||
| 15 | Jeremy Hellickson | 4.39 | 2015 | ||
| 16 | R.A. Dickey | 4.48 | 2015 | ||
| 17 | Wade Miley | 4.59 | 2016 | ||
| 18 | Andrew Cashner | 4.64 | 2020 | ||
| 19 | Alex Cobb | 4.68 | 2021 | ||
| 20 | R.A. Dickey | 4.77 | 2014 | ||
| 21 | Erasmo Ramirez | 4.77 | 2014 | ||
| 22 | Ricky Nolasco | 4.82 | 2017 | ||
| 23 | Erick Fedde | 4.82 | 2021 | ||
| 24 | Felix Hernandez | 4.86 | 2018 | ||
| 25 | Tyler Anderson | 4.86 | 2021 | ||