Can I put a course I took at another school in the Activities section?

I took an online course offered by Brown University over the summer on entrepreneurship and start-ups. The thing is, in the Common App, the only information I can put in is who offered the course, where I took it, and the duration of the course. But that’s leaving a lot out in my opinion.

I had to apply to the course and write an essay, send my transcripts and everything. And I also got a glowing evaluation from the professor that taught the course. Is there any way to reflect that in the application?

You need to send the transcript from the course to wherever you apply. That’s why they ask where you’ve taken courses, but not what. They’ll see what you took on the transcript.

You can also include the course in the additional information section.