Abstract
We classify all warped dS5 backgrounds in D = 11 supergravity with enhanced supersymmetry. We show that backgrounds preserving N = 16 supersymmetries consist of either a stack of M5 branes with transverse space $\mathbb{R}^5$, or a generalized M5-brane configuration with transverse space $\mathbb{R} \times N_4$, where N4 is a hyper-Kähler manifold and the M5-brane harmonic function is determined by a hyper-Kähler potential on N4. Moreover, we find that there are no backgrounds preserving exactly N = 24 supersymmetries. Backgrounds preserving N = 32 supersymmetries correspond to either $\mathbb{R}^{1,10}$ or $AdS_7\times S^4$.