| Career - ERA | |||
| Rk | Player Name | Totals | |
| 1 | Garrett Richards | 3.52 | |
| 2 | Matt Garza | 3.66 | |
| 3 | Tom Glavine | 3.68 | |
| 4 | Tyler Glasnow | 3.78 | |
| 5 | Adam Wainwright | 3.82 | |
| 6 | Kris Benson | 3.98 | |
| 7 | Kevin Brown | 4.08 | |
| 8 | Michael Pineda | 4.17 | |
| 9 | Brad Penny | 4.28 | |
| 10 | Jake Peavy | 4.30 | |
| 11 | Zack Greinke | 4.33 | |
| 12 | J.A. Happ | 4.42 | |
| 13 | Jameson Taillon | 4.53 | |
| 14 | Charles Nagy | 4.57 | |
| 15 | Frankie Montas | 4.59 | |
| 16 | Eric Milton | 4.67 | |
| 17 | Jaime Garcia | 4.76 | |
| 18 | Jarrod Washburn | 4.77 | |
| 19 | Al Leiter | 4.90 | |
| Single Season - ERA | |||||
| Rk | Player Name | Totals | Year | ||
| 1 | Garrett Richards | 2.19 | 2015 | ||
| 2 | Kutter Crawford | 2.56 | 2024 | ||
| 3 | Tom Glavine | 2.64 | 1998 | ||
| 4 | Jake Peavy | 2.66 | 2008 | ||
| 5 | Adam Wainwright | 2.67 | 2015 | ||
| 6 | Tom Glavine | 2.69 | 1997 | ||
| 7 | Kyle Bradish | 2.86 | 2024 | ||
| 8 | Tyler Glasnow | 2.96 | 2022 | ||
| 9 | Nathan Eovaldi | 2.98 | 2019 | ||
| 10 | Adam Wainwright | 3.11 | 2010 | ||
| 11 | Scott Baker | 3.12 | 2006 | ||
| 12 | Travis Wood | 3.24 | 2011 | ||
| 13 | Adam Wainwright | 3.30 | 2011 | ||
| 14 | Matt Garza | 3.33 | 2014 | ||
| 15 | Tyler Glasnow | 3.52 | 2024 | ||
| 16 | Jake Peavy | 3.65 | 2012 | ||
| 17 | Kris Benson | 3.66 | 2000 | ||
| 18 | Randy Johnson | 3.75 | 2007 | ||
| 19 | Frankie Montas | 3.75 | 2022 | ||
| 20 | Zack Greinke | 3.81 | 2022 | ||
| 21 | Danny Haren | 3.84 | 2006 | ||
| 22 | Charles Nagy | 3.87 | 1995 | ||
| 23 | Joe Musgrove | 3.88 | 2019 | ||
| 24 | Jameson Taillon | 3.88 | 2019 | ||
| 25 | Jameson Taillon | 3.89 | 2022 | ||