Studies in countability have uncovered a range of ontological entities which permit counting, including natural concrete individuals, discrete events, and taxonomic subkinds. Identifying the reasons why nominal referents may not be counted has been less successful, however, and remains controversial. This paper examines nouns that are “strongly non-countable”, those nouns for which combination with the plural marker, quantifiers, and nearly all other forms of determination is a vanishingly rare event. This paper develops a data set of nearly 500 such nouns, adducing their strongly non-countable status from usage over a 350 million word corpus (Davies 2009). Through further internet searches, we attest rare, but possible, patterns of coercion available to these nouns. We then develop a classification of the different notional categories that these nouns belong to. Finally, we examine broad distributional patterns and argue that these strongly non-countable nouns contrast with countable nouns as to their patterns of usage, in particular, being less discourse-salient and less referential than their count noun counterparts.