diff --git a/cmd/server.go b/cmd/server.go
index 7e7d1b22d8..de4ce52403 100644
--- a/cmd/server.go
+++ b/cmd/server.go
@@ -67,6 +67,7 @@ const (
 	GitlabWebhookSecretFlag    = "gitlab-webhook-secret" // nolint: gosec
 	HidePrevPlanComments       = "hide-prev-plan-comments"
 	LogLevelFlag               = "log-level"
+	ParallelPoolSize           = "parallel-pool-size"
 	AllowDraftPRs              = "allow-draft-prs"
 	PortFlag                   = "port"
 	RepoConfigFlag             = "repo-config"
@@ -87,18 +88,19 @@ const (
 	WriteGitCredsFlag          = "write-git-creds"
 
 	// NOTE: Must manually set these as defaults in the setDefaults function.
-	DefaultADBasicUser      = ""
-	DefaultADBasicPassword  = ""
-	DefaultCheckoutStrategy = "branch"
-	DefaultBitbucketBaseURL = bitbucketcloud.BaseURL
-	DefaultDataDir          = "~/.atlantis"
-	DefaultGHHostname       = "github.com"
-	DefaultGitlabHostname   = "gitlab.com"
-	DefaultLogLevel         = "info"
-	DefaultPort             = 4141
-	DefaultTFDownloadURL    = "https://releases.hashicorp.com"
-	DefaultTFEHostname      = "app.terraform.io"
-	DefaultVCSStatusName    = "atlantis"
+	DefaultADBasicUser           = ""
+	DefaultADBasicPassword       = ""
+	DefaultCheckoutStrategy      = "branch"
+	DefaultBitbucketBaseURL      = bitbucketcloud.BaseURL
+	DefaultDataDir               = "~/.atlantis"
+	DefaultGHHostname            = "github.com"
+	DefaultGitlabHostname        = "gitlab.com"
+	DefaultLogLevel              = "info"
+	DefaultParallelPlansPoolSize = 15
+	DefaultPort                  = 4141
+	DefaultTFDownloadURL         = "https://releases.hashicorp.com"
+	DefaultTFEHostname           = "app.terraform.io"
+	DefaultVCSStatusName         = "atlantis"
 )
 
 var stringFlags = map[string]stringFlag{
@@ -308,6 +310,10 @@ var boolFlags = map[string]boolFlag{
 	},
 }
 var intFlags = map[string]intFlag{
+	ParallelPlansPoolSize: {
+		description:  "Max size of the wait group that runs parallel plans and applies (if enabled).",
+		defaultValue: DefaultParallelPlansPoolSize,
+	},
 	PortFlag: {
 		description:  "Port to bind to.",
 		defaultValue: DefaultPort,
diff --git a/runatlantis.io/docs/server-configuration.md b/runatlantis.io/docs/server-configuration.md
index 78ff63b4b5..4a945e96a4 100644
--- a/runatlantis.io/docs/server-configuration.md
+++ b/runatlantis.io/docs/server-configuration.md
@@ -327,6 +327,12 @@ Values are chosen in this order:
   ```
   Log level. Defaults to `info`.
 
+* ### `--parallel-pool-size`
+  ```bash
+  atlantis server --parallel-pool-size=100
+  ```
+  Max size of the wait group that runs parallel plans and applies (if enabled). Defaults to `15`
+
 * ### `--port`
   ```bash
   atlantis server --port=8080
diff --git a/server/events/command_runner.go b/server/events/command_runner.go
index 1c4f02505a..089f1f679c 100644
--- a/server/events/command_runner.go
+++ b/server/events/command_runner.go
@@ -81,6 +81,9 @@ type DefaultCommandRunner struct {
 	Logger                   logging.SimpleLogging
 	// AllowForkPRs controls whether we operate on pull requests from forks.
 	AllowForkPRs bool
+	// ParallelPoolSize controls the size of the wait group used to run
+	// parallel plans and applies (if enabled).
+	ParallelPoolSize int
 	// AllowForkPRsFlag is the name of the flag that controls fork PR's. We use
 	// this in our error message back to the user on a forked PR so they know
 	// how to enable this functionality.
@@ -400,7 +403,7 @@ func (c *DefaultCommandRunner) runProjectCmdsParallel(cmds []models.ProjectComma
 	var results []models.ProjectResult
 	mux := &sync.Mutex{}
 
-	wg := sizedwaitgroup.New(15)
+	wg := sizedwaitgroup.New(c.ParallelPlansPoolSize)
 	for _, pCmd := range cmds {
 		pCmd := pCmd
 		var execute func()
diff --git a/server/server.go b/server/server.go
index c348c2e90a..43a461c4fd 100644
--- a/server/server.go
+++ b/server/server.go
@@ -369,6 +369,7 @@ func NewServer(userConfig UserConfig, config Config) (*Server, error) {
 		SilenceForkPRErrorsFlag:  config.SilenceForkPRErrorsFlag,
 		SilenceVCSStatusNoPlans:  userConfig.SilenceVCSStatusNoPlans,
 		DisableApplyAll:          userConfig.DisableApplyAll,
+		ParallelPoolSize:         userConfig.ParallelPoolSize,
 		ProjectCommandBuilder: &events.DefaultProjectCommandBuilder{
 			ParserValidator:   validator,
 			ProjectFinder:     &events.DefaultProjectFinder{},
diff --git a/server/user_config.go b/server/user_config.go
index 8064ca168a..5736d73b6a 100644
--- a/server/user_config.go
+++ b/server/user_config.go
@@ -37,6 +37,7 @@ type UserConfig struct {
 	GitlabWebhookSecret        string `mapstructure:"gitlab-webhook-secret"`
 	HidePrevPlanComments       bool   `mapstructure:"hide-prev-plan-comments"`
 	LogLevel                   string `mapstructure:"log-level"`
+	ParallelPoolSize           int    `mapstructure:"parallel-pool-size"`
 	PlanDrafts                 bool   `mapstructure:"allow-draft-prs"`
 	Port                       int    `mapstructure:"port"`
 	RepoConfig                 string `mapstructure:"repo-config"`