Ulrich W. Kulisch (born 1933 in Breslau) is a German mathematician specializing in numerical analysis, including the computer implementation of interval arithmetic.
After graduation from high school in Freising, Kulisch studied mathematics at the University of Munich and the Technical University of Munich where in 1961 he completed his dissertation (Behandlung von Differentialgleichungen im Komplexen auf dem elektronischen Analogrechner) under Josef Heinhold.
He spent time in 1969/1970 at the Mathematics Research Center of the University of Wisconsin–Madison under Ramon Edgar Moore; in 1972/1973 and 1978/1979 at IBM's Thomas J. Watson Research Center in Yorktown Heights (where he worked alongside Willard L. Miranker (1932–2011)); and in 1998 and 1999/2000 at the Electrotechnical Laboratory at the University of Tsukuba.
Kulisch developed software with automated results verification including Nixdorf Computer (Pascal-XSC and others), IBM (projects ACRITH and ACRITH-XSC) and Siemens (program package ARITHMOS).
In 1993/1994 he was also involved in a hardware implementation on the XPA 3233 vector arithmetic coprocessor.