西西兰郡（丹麦语：Vestsjællands Amt）是丹麦西兰岛西北部的郡。2007年1月1日被并入西兰大区。

Vestsjællands Amt (English: West Zealand County) is a former county (Danish: amt) in the west-central part of the island of Zealand (Sjælland) in eastern Denmark. The county was formed on 1 April 1970, comprising a few former counties. The county was abolished effective January 1, 2007, when it merged into Region Sjælland (i.e. Region Zealand).