HH may refer to:
The HH Ferry route (About the name: Helsingør - Helsinborg; Helsingør is Danish for Elsinore) is a very old shipping route which connects Elsinore (Helsingør) at Zealand, Denmark and Helsingborg, Scania, Sweden across the northern, and narrowest part of the Øresund.
The h/h blood group, also known as Oh or the Bombay blood group, is a rare blood type. This blood phenotype was first discovered in Bombay, now known as Mumbai, in India, by Dr. Y. M.
Human Herpes Virus (HHV) Infected Cell Polypeptide 0 (ICP0) is a protein, encoded by the DNA of herpes viruses.
HHL Leipzig Graduate School of Management, formerly known as Handelshochschule Leipzig, is a private business school based in Saxony, Germany.
HipHop Virtual Machine (HHVM) is an open-source virtual machine based on just-in-time (JIT) compilation that serves as an execution engine for the PHP and Hack programming language.