初等数学（英语：Elementary mathematics），简称初数，是指通常在小学或中学阶段所教的数学内容，与高等数学相对。

从公元前5世纪到17世纪属于初等数学时期，高等数学的创建结束了初等数学时期。这个时期创立了系统地的初等数学，包括算术、初等代数、平面几何、立体几何和平面三角等内容。

Elementary mathematics consists of mathematics topics frequently taught at the primary or secondary school levels.

The most basic topics in elementary mathematics are arithmetic and geometry. Beginning in the last decades of the 20th century, there has been an increased emphasis on problem solving. Elementary mathematics is used in everyday life in such activities as making change, cooking, buying and selling stock, and gambling. It is also an essential first step on the path to understanding science.