We describe SemEval-2021 task 6 on Detection of Persuasion Techniques in\nTexts and Images: the data, the annotation guidelines, the evaluation setup,\nthe results, and the participating systems. The task focused on memes and had\nthree subtasks: (i) detecting the techniques in the text, (ii) detecting the\ntext spans where the techniques are used, and (iii) detecting techniques in the\nentire meme, i.e., both in the text and in the image. It was a popular task,\nattracting 71 registrations, and 22 teams that eventually made an official\nsubmission on the test set. The evaluation results for the third subtask\nconfirmed the importance of both modalities, the text and the image. Moreover,\nsome teams reported benefits when not just combining the two modalities, e.g.,\nby using early or late fusion, but rather modeling the interaction between them\nin a joint model.\n