Maddinson was called up alongside reserve wicketkeeper Sam Harper after Josh Inglis was ruled out of the first test, which begins in Durban on October 9, with a fractured finger.
Maddinson's inclusion comes amid growing injury problems for the tourists, who are also monitoring Cameron Green after he suffered an abdominal strain during the third One-Day International against South Africa.
"Sam gives us wicketkeeping cover as Josh continues his recovery while Nic provides flexibility throughout the batting order," chief selector George Bailey said.
Maddinson played three tests in 2016 but has not featured in the format in almost a decade and has yet to play a first-class match since undergoing chemotherapy following a cancer diagnosis last year.
Despite not playing Sheffield Shield cricket last season, the left-hander was named New South Wales captain for the current campaign and scored a century in the One-Day Cup last week.
Harper has earned his first senior Australia call-up after strong recent form, including a century for Australia A, and will provide cover for first-choice wicketkeeper Alex Carey.