This book constitutes the refereed proceedings of the 27th ATEE Spring Conference on Social Justice, Media and Technology, ATEE 2021, held in Florence, Italy, during October 28-30, 2021. The 19 full papers included in this book were carefully reviewed and selected from 49 submissions. They were organized in topical sections as follows: teaching critical media/digital literacy in multicultural societies; decommodifying teacher (digital) education; and digital technology and equity for inclusive teaching.