Odd has several meanings.

• Within mathematics:
  • an integer is odd if it cannot be divided by two; see even and odd numbers
  • a function f defined on the real numbers is odd if f(x) = −f(−x) for all x; see even and odd functions
  • a permutation of a finite set is odd if it can be written as the composition of an odd number of transpositions; see even and odd permutations
• Odd is also a name of Norse origin, in current use as a masculine name in Norway. It is the name of a character in Code Lyoko.