Raikkonen briefly led during the first round of pit stops and was in podium contention throughout, running third until the final five laps when Williams' Valtteri Bottas was able to slip by along the Kemmel straight. Fourth still represented Raikkonen's best result since rejoining Ferrari, and marked the first time this year he has beaten team mate Fernando Alonso over a race distance.
Asked about his performance, the Finn - a four-time winner in Belgium - said an incident-free race had been the primary cause of his resurgence.
"We had decided to tackle this race more aggressively, making an early stop to get ahead of the cars that had yet to pit and that meant I was able to stay with the leaders for much of the race," he explained.
"We did our utmost and for the first time, we managed to have a clean race without any problems.
"When Bottas in the Williams began to close on me, I knew I didn't have the speed to defend on the straight and with a few laps to go, he managed to pass me.
"In general, I'm happy with how this weekend ended. We knew it would not be easy on this circuit, but the car has improved and today the pace was good.
"Fourth place shows we are going in the right direction, but it doesn't mean we can settle for that. Today, we scored a good number of points, but we are here to win and we will continue to work to reach the top."
Ferrari team principal Marco Mattiacci praised Raikkonen's efforts, while admitting the team had cost Alonso the chance to also fight for the podium after his mechanics were still working on his car when the grid formation lap began, earning the Spaniard a five-second stop-go penalty.
"We are very pleased for Kimi: today, he came close to the podium and scored his best result of the season, a result which sees us maintain third place in the constructors' classification," Mattiacci said.
"Unfortunately, Fernando's race was compromised by a problem at the start. Without that, I firmly believe the podium was within his reach.
"We know we have missed out on a great opportunity, but we will learn from this incident to pay obsessive attention to our procedures, as we strive to improve reliability."
Ferrari's focus now moves on to the Italian team's home race at Monza in two weeks' time.
"The next race will be complicated because top speed is a strong point of the Mercedes-powered teams," added Mattiacci. "We will try and defend with every means available, because the efforts of the team in terms of improving the car are producing encouraging signs."