Inga-Britt Monica Stigsdotter Ahlenius (born 19 April 1939) is a Swedish auditor, public servant and former Under-Secretary-General for the United Nations Office of Internal Oversight Services (OIOS).

[2] She served as Auditor General of the Swedish National Audit Office from 1993 to 2003.

There was some controversy when her term as Auditor General was over where she made several statements to media including that some of the government's proposed changes to the Audit Office would limit its ability to act independently.

[1] The previous controversy from 2003 was noted by Swedish media since Mrs. Ahlenius was proposed for the position by the United States and not by her native Sweden.

Ahlenius was appointed Under-Secretary-General for United Nations Office of Internal Oversight Services for a five-year term starting on 15 July 2005.