Flourish Pixel

Remove/Exclude specific categories from site RSS Feed. You just need to install this, then place your category id in it’s option page and save. That’s all. If you want to exclude more than one category, then place them one by one and separate them by comma.
For Example: -1,-2
**Note: you must need to use minus sign (-) before category id.

FP RSS Category Excluder

Remove/Exclude certain categories from site RSS Feed.

Tranons

A simplistic plugin that allows for the furthur customization of your category list. This will allow you to create a custom category list which will show the categories you want, and will hide the categories you do not want. For example, say you have a particular category you don’t want to be displayed named “Announcements”. You can use this plugin to display all of your other categories, except the category “Announcements”. You are not limited to just excluding one category; you can exclude multiple categories. Essentially, this plugin provides more functionality to your category list.

Category Excluder Widget

This widget allows you to easily create a specific category list. You can exclude any categories you please.

FP RSS Category Excluder vs Category Excluder Widget