The 23-year-old, who joined the club from West Coast for 2012, has become a key member of the Power midfield.
Ebert is a fourth generation player for the club, with the likes of his uncle Russell and father Craig legends at Port Adelaide.
"I've had a fair few family members play at the club and that was a big reason for me to come back (from West Coast) to play for the club I loved and followed growing up," Ebert said.
"It's exciting to continue that on for the next few years.
"I think it's a really exciting young group, everyone is really on-board and looking to work hard and better themselves."
Power coach Ken Hinkley described Ebert, who has played 122 games at AFL level, as a superb leader and model professional when it comes to his football.
"The best way to describe Brad, which I believe is the ultimate compliment for any footballer, is that he's a pro," Hinkley said.
"A 'pro' doesn't leave anything in the tank, gets the most out of his ability and gives his all to the cause - that's Brad.
"The Ebert name is an important name for the Port Adelaide Football Club, we love that he's adding to the standard and tradition that name has here and starting to set standards of his own."