This entry proceeds as follows. In the next section we discuss the most unproblematic technical use of information in biology, which draws on Shannon and the mathematical theory of information. Against that background, some of the more contentious uses are both motivated and introduced. In section 3, we discuss recent attempts to build a richer concept out of Shannon’s technical notion. We then discuss the status of the “genetic code” in its original sense (section 4), and signalling systems inside and outside of genetics (section 5). We then look at ways of rejecting informational forms of description (section 6). The key sceptical idea is the so-called “parity thesis”: the idea that while genes play an immensely important role in evolution and development, so do other factors, and so it is a mistake to think of genes and only genes as instructing or controlling these processes. The final two sections discuss the idea that biological development in individuals proceeds by the execution of a program (section 7), and the use of information in understanding the role of inheritance systems in the “major transitions” in evolution (section 8).