In this paper, we introduce the MediaSpin dataset aiming to help in the development of models that can detect different forms of media bias present in news headlines, developed through human-supervised and -validated Large Language Model (LLM) labeling of media bias. This corpus comprises 78,910 pairs of news headlines and annotations with explanations of the 13 distinct types of media bias categories assigned. We demonstrate the usefulness of our dataset for automated bias detection in news edits.