Last week I noticed category list on my WordPress theme is not sorted the way I like. So, I checked category widgets and It did not have any option to sort it. Moreover, I checked post categories and all I found was how to create new category. This is really odd that WordPress developers did not put this capability to it. With a quick search on Google I found really useful plugin which is called “My Category Order”. All you should do is installing it and drag the generated widget to your sidebar. I think WordPress developers should replace this plugin with the default one.
Here is the link to access this plugin >> Download My Category Order Plugin