Where is my personal profile for Mozilla Firefox located on my Mac computer?

You personal profile for Mozilla Firefox is located under your home folder:

$ cd /Users/{user}/Library/Application\ Support/Firefox/
$ ls -l 
drwx------  5 {user}  staff  170 Nov  2 09:07 Crash Reports
drwx------  2 {user}  staff   68 Jan 30  2022 Pending Pings
drwx------@ 4 {user}  staff  136 Jan 30  2022 Profiles
-rw-r--r--@ 1 {user}  staff   71 Jan 30  2022 installs.ini
-rw-r--r--@ 1 {user}  staff  286 Jan 30  2022 profiles.ini

$ ls -l Profiles
drwx------@ 49 {user}  staff  1666 Nov  2 17:35 g51k69rs.default-release
drwx------@  6 {user}  staff   204 Feb  7  2022 gywrugwu.default

$ ls -l Profiles/gywrugwu.default
-rw-------  1 {user}  staff  16384 Oct 24 11:26 key3.db
-rw-------  1 {user}  staff  16384 Feb  7  2022 secmod.db
-rwx------@ 1 {user}  staff     47 Jan 30  2022 times.json

$ ls -l Profiles/g51k69rs.default-release
-rw-r--r--@ 1 {user}  staff     5608 Nov  2 17:35 AlternateServices.txt
-rw-r--r--@ 1 {user}  staff     1973 Nov  2 09:19 ExperimentStoreData.json
-rw-r--r--@ 1 {user}  staff     2196 Nov  2 17:35 SiteSecurityServiceState.txt
-rw-r--r--@ 1 {user}  staff     7743 Nov  2 17:28 addonStartup.json.lz4
-rw-r--r--@ 1 {user}  staff     2179 Nov  2 17:28 addons.json
drwxr-xr-x@ 4 {user}  staff      136 Nov  2 10:13 bookmarkbackups
-rw-r--r--@ 1 {user}  staff      216 Nov  2 17:35 broadcast-listeners.json
-rw-------@ 1 {user}  staff   229376 Nov  2 16:01 cert9.db
-rw-------@ 1 {user}  staff      220 Nov  2 09:07 compatibility.ini
-rw-r--r--@ 1 {user}  staff      939 Jan 30  2022 containers.json
-rw-r--r--@ 1 {user}  staff   229376 Jan 30  2022 content-prefs.sqlite
-rw-r--r--@ 1 {user}  staff   524288 Nov  2 17:23 cookies.sqlite
-rw-r--r--@ 1 {user}  staff   459120 Nov  2 17:27 cookies.sqlite-wal
drwx------@ 4 {user}  staff      136 Nov  2 17:26 crashes
drwxr-xr-x@ 7 {user}  staff      238 Nov  2 17:36 datareporting
-rw-r--r--@ 1 {user}  staff     1895 Nov  2 09:13 extension-preferences.json
drwxr-xr-x@ 3 {user}  staff      102 Nov  2 17:28 extensions
-rw-r--r--@ 1 {user}  staff    72712 Nov  2 17:28 extensions.json
-rw-r--r--@ 1 {user}  staff  5242880 Nov  2 17:23 favicons.sqlite
-rw-r--r--@ 1 {user}  staff   262368 Nov  2 17:28 favicons.sqlite-wal
-rw-r--r--@ 1 {user}  staff   262144 Nov  2 16:26 formhistory.sqlite
drwxr-xr-x@ 3 {user}  staff      102 Nov  2 09:15 gmp-gmpopenh264
drwxr-xr-x@ 3 {user}  staff      102 Nov  2 09:15 gmp-widevinecdm
-rw-r--r--@ 1 {user}  staff      808 Nov  2 09:07 handlers.json
-rw-------@ 1 {user}  staff   294912 Jan 30  2022 key4.db
drwx------@ 2 {user}  staff       68 Jan 30  2022 minidumps
-rw-r--r--@ 1 {user}  staff    98304 Nov  2 17:31 permissions.sqlite
-rw-------@ 1 {user}  staff      507 Jan 30  2022 pkcs11.txt
-rw-r--r--@ 1 {user}  staff  5242880 Nov  2 17:28 places.sqlite
-rw-r--r--@ 1 {user}  staff  2033136 Nov  2 17:28 places.sqlite-wal
-rw-------@ 1 {user}  staff    14817 Nov  2 17:28 prefs.js
-rw-r--r--@ 1 {user}  staff    65536 Nov  2 17:25 protections.sqlite
drwx------@ 2 {user}  staff       68 Nov  2 17:23 saved-telemetry-pings
-rw-r--r--@ 1 {user}  staff      284 Nov  2 09:07 search.json.mozlz4
drwxr-xr-x@ 3 {user}  staff      102 Jan 30  2022 security_state
-rw-r--r--@ 1 {user}  staff       90 Nov  2 17:25 sessionCheckpoints.json
drwxr-xr-x@ 7 {user}  staff      238 Nov  2 17:31 sessionstore-backups
drwxr-xr-x@ 3 {user}  staff      102 Nov  2 09:07 settings
-rw-r--r--@ 1 {user}  staff      896 Nov  2 09:07 shield-preference-experiments.json
drwxr-xr-x@ 6 {user}  staff      204 Jan 30  2022 storage
-rw-r--r--@ 1 {user}  staff     4096 Nov  2 17:27 storage.sqlite
-rw-r--r--@ 1 {user}  staff     4481 Nov  2 17:25 targeting.snapshot.json
-rwx------@ 1 {user}  staff       50 Jan 30  2022 times.json
drwxr-xr-x@ 4 {user}  staff      136 Nov  2 16:24 weave
-rw-r--r--@ 1 {user}  staff    98304 Jan 30  2022 webappsstore.sqlite
-rw-r--r--@ 1 {user}  staff      216 Nov  2 17:31 xulstore.json

Your profile is also cached in your home directory:

$ cd /Users/{user}/Library/Caches/Firefox/Profiles
$ ls -l
drwx------@ 9 {user}  staff  306 Nov  2 16:42 g51k69rs.default-release
drwx------@ 2 {user}  staff   68 Jan 30  2022 gywrugwu.default

There are other Firefox files located on your Mac computer:

• "/Users/{user}/Library/Application\ Support/Firefox/" - Personal profile for a given user.
• "/Users/{user}/Library/Caches/Firefox/" - Cached copy of the personal profile for a given user.
• "/Users/{user}/Library/Mozilla/" - Has an empty "Extensions" sub-folder.
• "/Library/Application\ Support/Mozilla/" - Setting shared by all users.
• "/Applications/Firefox.app/" - Program files for all users.

⇒ Personal Profile Deleted on Mac

⇐ First Time Open Mozilla Firefox on Mac

⇑ Using Mozilla Firefox on Mac Computer

⇑⇑ Firefox - Frequently Asked Questions