Not much has changed in the list of all-time team leaders since I compiled similar figures after 15 seasons (through 2019), other than Juan Soto making an appearance in several categories.
If you rely on MLB.com or BaseballReference.com for an all-time list, you get one that includes the Expos. The Montreal team existed for 36 seasons, so several all-time franchise marks are still held by Expos greats such as Tim Raines, Vladimir Guerrero and Steve Rogers.
Still, thanks in no small part to his long career with the Nats, Ryan Zimmerman tops the all-time franchise-leader board in games played, at bats, run scored, hits, doubles, home runs and RBIs. And he continues to lead all Nationals by a large margin in the same categories, as he did after 15 seasons.
Likewise, Stephen Strasburg and Max Scherzer are all-time franchise leaders in several major pitching categories. Stras is tops in games starts, innings pitched and strikeouts. Max has the lowest WHIP and batting-average against by a wide margin over all other Expos/Nationals who pitched a significant number of innings.
Here are the Nationals’ all-time leaders through 2024 (bold=also franchise leader):
HITTING
Game played
Ryan Zimmerman 1,799
Bryce Harper 927
Ian Desmond 927
Anthony Rendon 916
Jayson Werth 808
At Bats
Zimmerman 6,654
Desmond 3,480
Rendon 3,424
Harper 3,306
Werth 2,965
Runs scored
Zimmerman 963
Harper 610
Rendon 571
Werth 450
Trea Turner 444
Batting Average (3-season min.)
Daniel Murphy .329 (1,380 plate appearances)
Turner .300 (2,802 PAs)
Michael Morse .294 (1,353 PAs)
Denard Span .292 (1,605 PAs)
Juan Soto .291 (2,439 PAs)
Rendon .290 (3,927 PAs)
Base Hits
Zimmerman 1,846
Rendon 994
Harper 922
Desmond 917
Doubles
Zimmerman 417
Rendon 245
Desmond 185
Harper 183
Werth 162
Triples
Turner 32
Cristian Guzman 28
Zimmerman 22
Desmond 21
Span 19
Home Runs
Zimmerman 284
Harper 184
Rendon 136
Juan Soto 119
Desmond 110
Runs Batted In
Zimmerman 1,061
Rendon 546
Harper 521
Desmond 432
Werth 393
Base on Balls
Zimmerman 646
Harper 585
Soto 464
Rendon 409
Werth 403
Stolen Bases
Turner 192
Desmond 122
CJ Abrams 84
Michael A. Taylor 77
Harper 75
On-Base Percentage
Juan Soto .427
Nick Johnson .418 (in D.C.)
Harper .388
Rendon .368
Turner .356
Slugging Average
Soto .538
Harper .512
Rendon .490
Turner .486
Zimmerman .475
On-Base+Slugging
Soto .966
Harper .900
Rendon .859
Turner .842
Zimmerman .816
PITCHING
Victories 
Stephen Strasburg 113
Max Scherzer 92
Gio Gonzalez 86
Jordan Zimmermann 70
Tanner Roark 64
Innings Pitched
Strasburg 1,479
Gonzalez 1,253.1
Scherzer 1,229
Zimmermann 1,094
Patrick Corbin 946.2
Strikeouts
Strasburg 1,723
Scherzer 1,610
Gonzalez 1,215
Zimmermann 903
Corbin 832
Walks+Hits per Innings Pitched
Scherzer 0.96
Strasburg 1.10
Zimmermann 1.16
Roark 1.21
Gonzalez 1.28
Batting-Average Against
Scherzer .201
Strasburg .223
Gonzalez .239
Roark .247
Zimmermann .252
Saves/Save Opportunities/Successful
Chad Cordero 113/133 (84.9%)
Drew Storen 95/116 (81.8%)
Kyle Finnegan 88/110 (80%)
Sean Doolittle 75/83 (90.3%)
Rafael Soriano 75/88 (80.6%)
On the negative side for hitters, Zimmerman is the Montreal/Washington franchise leader in striking out (1,384 times). Among pitchers, Corbin gave up the most home runs (156) of any pitcher in franchise history. Strasburg hit the most batters (53).
With a young roster going into 2025 and no player with five-years tenure with Washington, these all-time standings are likely to remain in place at least for several more seasons.
Washington baseball history 