Vettel's deal with Ferrari expires at the end of the season but Hamilton believes the 30-year-old would not join Mercedes, as he is unlikely to accept driving for a team where both drivers are granted equal status.
This season, Ferrari have made it clear that Vettel is their number one driver ahead of Kimi Raikkonen, favouring the former over the latter at Monaco and in Hungary.
Raikkonen's contract was renewed earlier this week, a move which many interpreted as a reward for the Finn's acceptance of his second driver role and his support to his teammate.
"I know he doesn't want to be my team‑mate," Hamilton told reporters at a press conference in Spa, ahead of Sunday's (27 August) Belgian Grand Prix.
"He would not be in the position he is now in his team in terms of how the team operate if he was here. I am always game to race whoever it is and racing against the best drivers is always a great thing."
While the roles within Ferrari are well defined, Hamilton returned third place to teammate Valtteri Bottas in Hungary to honour a previous agreement between the drivers. While the move could potentially be very costly in the context of the Formula 1 world championship where Hamilton trails Vettel by 11 points, for the Briton it epitomised his relationship with his teammate.
"The last race is one of the best examples of how great the team is currently," Hamilton added.
"Coming into this season I haven't changed a single thing that I do, but there is another new element in the team and it works."
Vettel is widely expected to join Raikkonen in extending his deal with Ferrari but insisted a decision would not be announced within the next two weeks as he praised his team for renewing the Finn's deal.
"It's quite straightforward to work with him," he said. "I think everybody who knows him knows he's quite straightforward. He's a good match, and obviously it is great to continue like that."
Vettel and Hamilton arrive in Belgium for what is one of the iconic stages of the world championship with four wins each and the latter, who will celebrate his 200th start this weekend, admitted this year's battle was taking its toll.
"You don't want your competitors to see if you are struggling mentally or physically, you don't ever want to show weakness," he said.
"But it is so challenging for everyone involved in our team and in the sport. As a competitor at the top level I take a lot of inspiration from other competitors: Serena [Williams], [Roger] Federer and [Valentino] Rossi and you see their experiences and try to take it on. But it is so draining."