Sylvia Hedenström filmed the encounter at her Burträsk summer house in August when the reindeer wandered into her garden and was met by her pet Spiffan.
"I didn't believe it. I stood there and thought the cat doesn't understand what's going on, that there's a reindeer in front of it. Then she tried to scare it away and mark her territory," the cat's owner laughed.
"Spiffan doesn't like any other animals. She loves people and is the world's nicest cat towards humans, but no animals. No other cats, dogs, nothing."
Watch the encounter here or below:
"I felt a bit bad for the poor reindeer, he seemed lonely. He must have stayed here when the rest of the reindeer were taken back to the hills, so he's on his own," she added.
Reindeer are moved between low and high ground by Sami herders according to different herding seasons.
READ ALSO: Inside Sweden's Sami reindeer pilgrimage
The friendly reindeer in the video later came back to Burträsk for one more visit, but after encountering an equally unwilling Spiffan – who then gave it a swipe on the nose – Hedenström hasn't spotted it since.
A similarly tense confrontation between two different species occurred in Sweden earlier this year, when an elk calf met a frightened golfer. The result was a chase fit for a cartoon. Watch it below.