View the original community article here
Last tested: Oct 25, 2019
We do have an open source R library called LookR for API 3.0. However, it's not supported and hasn't been updated recently (in the past 2+ years, use with caution). It calls the Looker API to get data into R.
There are talks of updating LookR to fit the new API versions, but it is still in its early stages.
This is another package that was put together by different people, not generated in the same way as our other currently supported SDK: https://github.com/looker-open-source/sdk-codegen and github.com/Rich1000/lookr
At this point in time, we'd recommend using Python if it's an option.