Tinyarray is a numerical array module for Python. The multi-dimensional arrays it provides are best thought of as (possibly nested) tuples of numbers that, unlike Python's built-in tuples, support mathematical operations. Like tuples, tinyarrays are hashable and immutable and thus can be used as dictionary keys. The module's interface is a subset of that of NumPy and hence should be familiar to many Python programmers. Tinyarray has been heavily optimized for small arrays: For example, common operations on 1-d arrays of length 3 run 3-7 times faster than with NumPy. When storing many small arrays, memory consumption is reduced by a factor of 3. In summary, Tinyarray is a more efficient alternative to NumPy when many separate small numerical arrays are to be used.