This entry discusses radical flexibility as a framework for thinking through and practising postdigital ethical relations. The synopsis outlines several conceptualizations and critiques of flexibility in education. The authors then consider postdigital accessibility, before highlighting how postdigital radical flexibility should ethically develop this relationship through the principles of disability and design justice. By moving beyond conventional framings of flexibility as a neutral or universally beneficial practice, the entry demonstrates how radical flexibility is entangled with power, agency, and responsibility. It argues that postdigital radical flexibility fosters a critical, justice-oriented approach to education, emphasizing relationality, accountability, and collective liberation.