Stooge sort is a recursive sorting algorithm. It is notable for its exceptionally poor time complexity of ${\displaystyle O(n^{\log 3/\log 1.5})}$ = ${\displaystyle O(n^{2.7095...})}$ The algorithm's running time is thus slower compared to reasonable sorting algorithms, and is slower than bubble sort, a canonical example of a fairly inefficient sort. It is, however, more efficient than Slowsort. The name comes from The Three Stooges.

The algorithm is defined as follows:

It is important to get the integer sort size used in the recursive calls by rounding the 2/3 upwards, e.g. rounding 2/3 of 5 should give 4 rather than 3, as otherwise the sort can fail on certain data.