Adelaide has re-signed its second player in as many days, after securing the key signing of Rory Sloane yesterday.
Douglas was due to become a free agent at season’s end but chose to extent his stay at the Crows until at least the end of 2018.
The 28-year-old said the lure of being a one club player was too good to refuse.
“I have always admired players who have stayed true to one club, and this all but guarantees I am a Crow for life,” Douglas said.
“Everyone at our club likes the direction in which we are heading and this playing group is yet to realise its full potential.
“We are desperately chasing team success and I want to do all I can to help.”
Douglas has played 160 games for Adelaide since being selected with pick No. 16 in the 2005 National Draft.
Read more at AFC.com.au