Yes, Tesla seats are leather. They are not made from real leather but a synthetic leather which is not animal-sourced.
Synthetic leather seats
Tesla first started adding synthetic leather seats in vehicles back in 2016 as an option. But over the years, it became a standard interior configuration after positive customer reactions.
These seats aren’t made from cow hides but from a fake, synthetic leather that’s more durable than the real deal.
Model 3 interior is now 100% leather-free 🐄 pic.twitter.com/2F47zp8A4T
— Tesla (@Tesla) August 31, 2019