The 32-year-old comes in as a replacement for New Zealand fast bowler Kyle Jamieson who was forced to withdraw from the T20 tournament due to a recurrence of a lower-back stress fracture.
Magala has never featured in the IPL before and went unsold in December's mini-auction but will join Chennai for his base price R1 116 496,50.
The burly paceman was a standout performer for champions Sunrisers Eastern Cape in the inaugural edition of the SA20 earlier this year.
Magala finished the competition as the joint-fifth highest wicket-taker with 14 scalps at an economy-rate of of 8.68.
He is also a handy lower-order batter and has two half-centuries in his domestic T20 career.
The IPL is set to kick off on 31 March with Chennai Super Kings taking on defending champions Gujarat Titans in Ahmedabad.