Legendary all-rounder Kallis had already stepped down from Test cricket in December, having represented the Proteas in 166 matches during a 19-year career, and announced his full retirement on Wednesday.
The 38-year-old will be remembered as one of the game's greatest all-rounders, with his record showing 13,289 runs and 292 wickets in the longest format of the game.
Kallis had planned to participate in the ICC World Cup in Australia and New Zealand next year, but conceded that it was a "bridge too far" and ultimately stood down from South Africa duty.
Smith - who himself retired from Test cricket earlier this year after skippering South Africa on 109 occasions - was glowing in his appraisal of his former team-mate.
"He was an ultimate professional," Smith said. "I think the thing is you knew when he was out there batting, or if you had him bowling, that he was going to give you 100 per cent.
"He had a great ability to understand the game in that moment. When he was bowling he thought like a batter, which was a huge strength, and as a batter, I think he kind of used his all-rounder skills in such a good way.
"That's what made him so brilliant. By having an unbelievable technique he had a really good understanding of what he needed to do to be successful."
Smith admits it will be difficult to replace a player of Kallis' ability, but feels there is more than enough talent in the team to keep South Africa competitive.
He added: "We're still blessed with so many wonderful players. How do you replace a Jacques Kallis? I don't know. But there's opportunities for players.
"Sometimes things take time. I think not having him there now does pass a little bit more pressure on to some of the guys who have been around for a long time, but I think there's enough established guys there."