In addition to good physical presence and skating, Moreau had shown a remarkable scoring touch in his draft year.

The Blackhawks allowed Moreau to play another year in junior (for Sudbury), before bringing him to their IHL team in Indianapolis.

On March 20, 1999, Moreau was dealt in a blockbuster trade to the Edmonton Oilers along with Chad Kilger, Daniel Cleary and Christian Laflamme in exchange for Boris Mironov, Dean McAmmond and Jonas Elofsson.

The following NHL season was cancelled due to the lockout, so Moreau played with EC VSV Villach of the Austrian Hockey League.

On October 6, 2006, Moreau was signed by the Oilers to a 4-year contract extension, staving off the unrestricted free agency and keeping the winger with the team through the 2010–2011 season.

On June 18, 2009, Ethan Moreau was awarded the King Clancy Memorial Trophy for best exemplifying leadership qualities on and off the ice and by also making significant humanitarian contributions to the Oilers Community Foundation.

[5] In 2016, he joined as the Niagara Purple Eagles men's ice hockey team as assistant coach of Dave Burkholder.