Mr Stewart ran to succeed Theresa May as prime minister and Tory leader in 2019 and came to prominence for his use of social media.
He resigned from the Conservative Party in 2019 after losing the whip from eventual leader Boris Johnson and stood down as MP for Penrith and the Border later that year.
Mr Stewart told Scotland on Sunday Scottish conservatism had “more in common” with the way he viewed the world, but was “struggling” about whether he wanted to go back into politics.
He said: “I think for somebody like me who is about the liberal centre, and obviously it would be a liberal Unionist centre in Scotland, I can see a real point to that, yes. And maybe that is something to think about in the long run.
“I’m still struggling about whether I want to go back into politics at all. But I think if I did go back into politics, I think that’s a very attractive, interesting thing.
“I care deeply about Scotland. I think Scottish Conservatism has more in common with the way that I view the world.”
The former minister also said a second independence referendum was “less relevant” than it was, but warned against complacency that the unionist side would win again.
He lamented the “shameful state” of politics and said the political culture both at Westminster and Holyrood were similar.
Mr Stewart said:”I don’t know Holyrood politics as well, but my sense of MSPs is that it’s a very similar culture to MPs,” he said.
“They have come to a similar formation. A lot of it is their priorities being very focused on just winning the next election, not really thinking hard in detail about policy.
“It’s very tribal; it’s very much about sticking it to the other side. It’s a culture where the press releases seem to substitute for policy.”
“I think this is true both sides of the border.”
A Scottish Conservative spokesman said: “Whether Rory Stewart chooses to apply for selection as a Scottish Conservative candidate is clearly a matter for him. But, if he did, his application would be carefully assessed, as every applicant’s is.”