Ingram, the 2016 T20 Blast Player of the Year in England, has again starred for Glamorgan in this year’s competition, scoring two centuries including a 46-ball ton last month.
The 32-year-old left-handed batter also bowls right-arm leg-spinners.
Strikers coach Jason Gillespie said the Strikers had been keeping an eye on Ingram for some time.
“The decision was made that we’d look over the world for an overseas batsman and we found a quality one in Colin,” he said.
“He’s a guy who can bat in the top four and who can make the crowd excited.
“He gives it a whack … he has a lot of T20 experience and adds a great deal to our batting line-up. I know that he’s absolutely thrilled and he’s really committed and really excited to be linking up with us."
Ingram played 31 one-day and nine Twenty20 international matches for South Africa.
He has also played in the Indian Premier League with the Delhi Daredevils.
The Adelaide Strikers open their KFC BBL|07 season at Adelaide Oval on Friday, December 22.
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