This article presents an overview of synthetic models of the CaMn
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O
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oxygen‐evolving complex (OEC) of Photosystem II, the site of OO bond formation during photosynthetic water oxidation. Model clusters are useful spectroscopic benchmarks and can be used to test hypotheses regarding uncertain structural or mechanistic aspects of the OEC. Due to the complexity, heterometallic composition, and asymmetric structure of the biological cluster, modeling the OEC has been synthetically challenging. Here, we describe synthetic strategies and characterization methods of manganese complexes. Selected examples are discussed, ranging from monometallic high‐valent manganese complexes to heterometallic manganese oxido clusters, along with the relevant insights derived from these studies with respect to biological water splitting. Finally, efforts toward using molecular and heterogeneous manganese‐oxido OEC models as artificial water oxidation catalysts will be discussed.