diff --git a/devtools/client/locales/en-US/responsive.properties b/devtools/client/locales/en-US/responsive.properties
index b9da1ab5b5c3..d26ac187f854 100644
--- a/devtools/client/locales/en-US/responsive.properties
+++ b/devtools/client/locales/en-US/responsive.properties
@@ -23,7 +23,7 @@ responsive.exit=Close Responsive Design Mode
 responsive.deviceListLoading=Loading…
 
 # LOCALIZATION NOTE (responsive.deviceListError): placeholder text for
-# device selector when an error occured
+# device selector when an error occurred
 responsive.deviceListError=No list available
 
 # LOCALIZATION NOTE (responsive.done): button text in the device list modal
diff --git a/devtools/shared/locales/en-US/gclicommands.properties b/devtools/shared/locales/en-US/gclicommands.properties
index 74d20335e352..a48941f71470 100644
--- a/devtools/shared/locales/en-US/gclicommands.properties
+++ b/devtools/shared/locales/en-US/gclicommands.properties
@@ -1457,7 +1457,7 @@ folderOpenDirResult=Opened %1$S
 # use of 'mdn' command.
 mdnDesc=Retrieve documentation from MDN
 # LOCALIZATION NOTE (mdnCssDesc) A very short string used to describe the
-# result of the 'mdn css' commmand.
+# result of the 'mdn css' command.
 mdnCssDesc=Retrieve documentation about a given CSS property name from MDN
 # LOCALIZATION NOTE (mdnCssProp) String used to describe the 'property name'
 # parameter used in the 'mdn css' command.
diff --git a/dom/locales/en-US/chrome/dom/dom.properties b/dom/locales/en-US/chrome/dom/dom.properties
index ea6d14521305..7584554fa250 100644
--- a/dom/locales/en-US/chrome/dom/dom.properties
+++ b/dom/locales/en-US/chrome/dom/dom.properties
@@ -97,7 +97,7 @@ MediaBufferSourceNodeResampleOutOfMemory=Insufficient memory to resample the Aud
 # LOCALIZATION NOTE: Do not translate decodeAudioData.
 MediaDecodeAudioDataUnknownContentType=The buffer passed to decodeAudioData contains an unknown content type.
 # LOCALIZATION NOTE: Do not translate decodeAudioData.
-MediaDecodeAudioDataUnknownError=An unknown error occured while processing decodeAudioData.
+MediaDecodeAudioDataUnknownError=An unknown error occurred while processing decodeAudioData.
 # LOCALIZATION NOTE: Do not translate decodeAudioData.
 MediaDecodeAudioDataInvalidContent=The buffer passed to decodeAudioData contains invalid content which cannot be decoded successfully.
 # LOCALIZATION NOTE: Do not translate decodeAudioData.
diff --git a/netwerk/locales/en-US/necko.properties b/netwerk/locales/en-US/necko.properties
index 431148a4db56..60607241df79 100644
--- a/netwerk/locales/en-US/necko.properties
+++ b/netwerk/locales/en-US/necko.properties
@@ -41,7 +41,7 @@ AutomaticAuth=You are about to log in to the site “%1$S” with the username 
 TrackingUriBlocked=The resource at “%1$S” was blocked because tracking protection is enabled.
 
 # LOCALIZATION NOTE (APIDeprecationWarning):
-# %1$S is the deprected API; %2$S is the API function that should be used.
+# %1$S is the deprecated API; %2$S is the API function that should be used.
 APIDeprecationWarning=Warning: ‘%1$S’ deprecated, please use ‘%2$S’
 
 # LOCALIZATION NOTE (nsICookieManagerDeprecated): don't localize originAttributes.
diff --git a/toolkit/locales/en-US/chrome/global/filepicker.properties b/toolkit/locales/en-US/chrome/global/filepicker.properties
index 69b0b1ca3e62..9c9be1f7850d 100644
--- a/toolkit/locales/en-US/chrome/global/filepicker.properties
+++ b/toolkit/locales/en-US/chrome/global/filepicker.properties
@@ -52,4 +52,4 @@ promptNewDirTitle=Create new directory
 promptNewDirMessage=Directory name:
 
 errorPathProblemTitle=Unknown Error
-errorPathProblemMessage=An unknown error occured (path %S)
+errorPathProblemMessage=An unknown error occurred (path %S)