Hamilton is now outright second on the all-time list behind Michael Schumacher, whose tally of seven he can match in 2020. The British driver wrapped up the title at Austin's Circuit of the Americas, finishing second behind Mercedes teammate Valtteri Bottas.
"It's just overwhelming if I'm really honest," Hamilton said after the race. "It was such a tough race today. Yesterday was a really difficult day for us and Valtteri did a fantastic job so a huge congratulations to him.
"Today I really just wanted to recover and deliver the one-two for the team and I didn't think the one stop would be possible but I worked as hard as I could."
Hamilton said the championship underlined his commitment to the words of advice his father gave him when he started karting as a boy.
"My dad told me when I was six or seven years old never to give up and that's kind of the family motto.
"I was pushing as hard as I could and I was hopeful I might be able to get the win today but I didn't have it in the tyres unfortunately. I feel so much emotion, it's an honour to be up there with those greats."