We introduce a generalisation of the traditional magic square which proves useful in the construction of magic labelings of graphs. An order n sparse semi-magic square is an x n array containing the entries 1,2, ..., m (for some m < n₂) once each with the remainder of its entires 0, and its rows and columns have a constant sum κ. We discover some of the basic properties of such arrays and provide constructions for squares of all orders n ≥3. We also show how these arrays can be used to produce vertex-magic labelings for certain families of graphs.