Other answers are valid, but not so straightforward, IMHO. So here is a very simple solution, as of 2020.
- Use the following link:
https://stackexchange.com/users/flair/2778822.png?theme=dark&latest
(usinglatest
keeps it up to date) - Replace
2778822
by your SO ID, found on your profile https://meta.stackoverflow.com/users/flair - (optional) Change the
theme
parameter (accepted values are listed on the previous link) - Use this link in your LinkedIn "About" section, as Link
- I personally used
StackOverflow - Moderator - Top 3%
as link's "Title", but you can use anything you like
Example with my LinkedIn profile: https://www.linkedin.com/in/ambroise-dhenain/
Here is what the "edit media" view looks like, as of 2020: