Ian Douglas Neilson is a South African civil engineer and politician who served as the Deputy Mayor of Cape Town from May 2009 to October 2021. He previously served as the Mayoral Committee Member for Finance from 2006 until 2016 and Executive Councillor for Safety and Health from 2000 until 2002.

The City of Cape Town is a metropolitan municipality that forms the local government of Cape Town and surrounding areas. As of the 2016 community survey, it had a population of 4,005,016.