Shared Federation Metadata. A data structures may be implemented in a networked computing environment including federation. A federation includes two or more organizations coupled in a fashion such that authentication and authorization statements span the organizations in accordance with a pre-defined policy. A computer readable medium may include a data structure. The data structure includes fields including at least one or more grouping of metadata about a first federation or about an organization within the first federation. At least one of the one or more groupings of metadata about the first federation or about an organization within the first federation are included in the data structure by a reference to a block of federation metadata, the block of federation metadata is used for at least one other federation or organization.