In molecular biology, SNORD116 (also known as HBII-85) is a non-coding RNA (ncRNA) molecule which functions in the modification of other small nuclear RNAs (snRNAs).

This type of modifying RNA is usually located in the nucleolus of the eukaryotic cell which is a major site of snRNA biogenesis.

Most of the members of the box C/D family function in directing site-specific 2'-O-methylation of substrate RNAs.

[2] Unlike most other snoRNAs, SNORD116 is expressed prevalently in the brain (but is absent in PWS patients) and lacks any significant complementarity with ribosomal RNA.

[3][4] More evidence comes from the discovery of two individuals that share many traits of PWS sufferers, both have atypical microdeletions on chromosome 15q11–13, the intersection of which contains only the SNORD116 snoRNAs.