Apparatus and method for efficient compression block decoding using content-addressable structure for header processing. For example, one embodiment of an apparatus comprises: a header parser to extract a sequence of tokens and corresponding length values from a header of a compression block, the tokens and corresponding length values associated with a type of compression used to compress a payload of the compression block; and a content-addressable data structure builder to construct a content-addressable data structure based on the tokens and length values, the content-addressable data structure builder to write an entry in the content-addressable data structure comprising a length value and a count value, the count value indicating a number of times the length value was previously written to an entry in the content-addressable data structure.