I am trying to use a Qlabel as a message center for relaying messages to users of the application. Some messages might be longer than allowed for the Qlabel and I want it to just scroll horizontally until the end of the text. How can I do this in a Qlabel? I cannot seem to find anything in designer and don't want to work out some sort of truncation method in code that just takes off pieces from the front of the string, that seems silly.
There's nothing in Qt that does that by default.  You will indeed need to create an animation that changes the text.
You can use QFontMetrics (label.fontMetrics()) to determine if the label text is larger than then QLabel (to know if you need to scroll it or not).  You need a way to repaint the QLabel every half second or so to animate the scrolling.  The easiest way is probably a QTimer.  The easiest method would probably be to subclass QLabel and have it check if it needs to scroll itself and reset the text every half second or so to simulate the scrolling.
If you wanted scrolling to be even smoother (at a sub-character level), you'd have to override the paint method and paint the text yourself translating and clipping it as necessary.
Smooth scrolling text in Qlabel