Twitterific is a Twitter widget for Mac OS X. It is one of the most popular twitter applications available. It allows Twitter users to view their Twitter feed and posts tweets without the use of a web browser. Twitterific is a third-party program, which means it was not developed by the Twitter, Inc. Rather, it was developed by a third-party company called Iconfactory. Additionally, it does not allow account sign ups via the program: users still have to sign up for a Twitter account via the official site, then configure Twitterific to work with that Twitter account.

Since Twitterific was designed to be a desktop widget, which is a micro-program that does only a small set of things, it was designed to be as compact as possible with regard to the amount of screen space it uses. It is also made to work with multiple Twitter accounts, which can be very useful to shared computers owners. The shareware version of the program is ad-supported, with a new ad appearing in users' public timelines among all of their tweets. The purchased version has no such ads.

With Apple's release of the iPad on April 3, 2010, a version of Twitterific specifically for the iPad was released two days earlier on April 1, 2010. This version is looking to match the success of its other iPhone OS, Twitterific for the iPhone, which was awarded the Apple Design Award for Best iPhone Social Networking Application in 2008.