Non-invertible symmetries in supergravity

Non-invertible symmetries have been extensively studied in quantum field theories in recent years. In this note we initiate their study in supergravity. We find infinite families of non-invertible defects in 11d and 10d Type II supergravities. These operators display a rich action on different probe branes. We comment on how these symmetries are removed in the UV completion, M-theory and Type II String Theory and how their existence strengthens the link between the absence of global symmetries in Quantum Gravity and the Completeness Hypothesis.