Marc-Édouard Vlasic (born March 30, 1987) is a Canadian professional ice hockey defenceman for the San Jose Sharks of the National Hockey League (NHL).
Vlasic was drafted by the San Jose Sharks 35th overall in the 2005 NHL Entry Draft, using a pick exchanged for goaltender Miikka Kiprusoff. Vlasic attended high school at Collège Sainte-Anne High School for three years, then a one-year stint at West Island College before making the jump to the Quebec Major Junior Hockey League (QMJHL), where he played three seasons of major junior hockey with the Quebec Remparts. He won the Memorial Cup with Quebec in 2006.
On August 27, 2008, the San Jose Sharks signed Vlasic to a four-year, $12.4 million contract extension that would keep him with the team through the 2012–13 NHL season. On July 11, 2012, the Sharks signed Vlasic to a 5-year, $21 million contract extension that will keep him with the Sharks through the 2017–2018 NHL season. Vlasic played only one game in the minors for the Worcester Sharks, in 2008, where he notched 2 points.