In mathematics, especially in geometry and group theory, a lattice in is a subgroup of which is isomorphic to , and which spans the real vector space . In other words, for any basis of , the subgroup of all linear combinations with integer coefficients forms a lattice. A lattice may be viewed as a regular tiling of a space by a primitive cell.

Lattice Group plc was a leading British gas transmission business. It was listed on the London Stock Exchange and was a constituent of the FTSE 100 Index.

In mathematics, the term lattice group is used for two distinct notions:

• a lattice (group), a discrete subgroup of Rⁿ and its generalizations.
• a lattice ordered group, a group that with a partial ordering that is a lattice order.