No, you will not lose your passwords if you uninstall Firefox. Uninstalling the browser does not delete any of the data stored within it, including saved passwords. However, once uninstalled, you won't be able to access those passwords unless you reinstall the program. To make sure that your passwords are safe and accessible in case of an emergency, it is recommended that you export them before uninstalling Firefox. This can be done by navigating to Options > Logins And Passwords > Saved Logins and selecting 'Export Logins'.