Ladislaus Josephovich Bortkiewicz was a Russian economist and statistician of Polish ancestry. He wrote a book showing how the Poisson distribution, a discrete probability distribution, can be useful in applied statistics, and he made contributions to mathematical economics. He lived most of his professional life in Germany, where he taught at Strassburg University and Berlin University (1901–1931).

In probability theory and statistics, the Poisson distribution is a discrete probability distribution that expresses the probability of a given number of events occurring in a fixed interval of time if these events occur with a known constant mean rate and independently of the time since the last event. It can also be used for the number of events in other types of intervals than time, and in dimension greater than 1.