Mark Nielsen may refer to:
*
Mark Nielsen (attorney)
Mark D. Nielsen is an American business executive, former elected official, and attorney.
Nielsen's current position is chief legal and regulatory officer of Frontier Communications Parent, Inc. (NASDAQ: FYBR), at the company's offices in Norwal ...
(born 1961), former Connecticut state senator
*
Mark Nielsen (tennis) (born 1977), former New Zealand tennis player
*Mark Nielsen (businessman) (born 1968), Australian businessman
{{Hndis, Nielsen, Mark