Hamilton, 33, missed out on winning his fifth world title as Raikkonen claimed his first race victory in over five years at the US Grand Prix.
Mercedes got their strategy all wrong as they pitted twice – once more than their rivals – and were unable to make up the time deficit.
Hamilton, who is a vocal advocate of making races much closer, was delighted to put on a thrilling show for his supporters, despite it ending in frustration for himself as he picked up the final podium place.
But he then revealed his plans to end his racing career within the next six years.
“Ferrari were quick and they did a great job today,” Hamilton said.
“I’m really happy for Kimi – he gave me a lot of confidence, I won’t go to his age, he doesn’t look any different since he started, so the Finnish blood is good.”
Hamilton was locked in a fierce battle with Raikkonen and Max Verstappen and the trio finished just seconds apart.
Meanwhile, Sebastian Vettel overtook Valtteri Bottas at the death to claim fourth place, just behind Hamilton, which means the Mercedes man must wait until the Mexican Grand Prix next weekend to win the Drivers’ Championship.
“It was epic, really exciting, not where I wanted to finish but I enjoyed the race and getting to be in a battle with these cars and these guys,” Hamilton added.
“People watching on TV want to see that more often. With the way these cars are designed we should be closer and have more races like that.
“They’ve got to do a better job with the design for 2021, so we can get closer together without having extra technology – if they can design something like that in a wind tunnel then that only means we need three-tenths behind to gain an advantage.
“I wasn’t feeling anything in the car today, I was just thinking I’ve got these two guys ahead of me who just want to win a race and they can take the risk but I can’t, I caught the marbles trying to overtake Max and it pulled me out.
“If it’s Max on the inside you give a lot of space… he might have been a long way away but I couldn’t see him.”
Raikkonen will celebrate ending a 113-race winning drought with his Ferrari colleagues.
“The champagne, is no different to last time on the podium… we always come to the weekend to do our best, and if we do our best then we expect to be up there to fight for the win. We did it today I felt confident and it worked out today,” he said.
“I never really made such a big thing out of it, I’ve won races and a Championship so it’s not like I’ve never done it.
“One more would never have changed my life – maybe others would look at me differently, but it’s not everything – it’s nice for sure but it’s not everything.”