When my mom caught my cutting in middle school she instantly threw my ass into an institution. The rest of my family judged me for it, and to this day are still convinced I'm influenced by the devil or something. For my family, that was a very radical and "crazy" thing for me to have done to myself at such a young age. And it was, but they failed to understand the reason I resorted to self harm.
When I first started dating my boyfriend, I don't think he even noticed. As time went on and we talked about my past childhood traumas, he was very loving and understanding when I showed him my cutting scars. I'm very lucky that he doesn't judge me for it. Even after 2 years together, it's not really something that bothers him.
On the other hand there's friends, randoms, and coworkers who have definitely noticed them. Most of them don't ask, but I did have a stranger point to my wrist and ask me where the scars came from. I was obviously embarrassed and anxious from being put on the spot, so I lied and said I fell out of a tree.

Not sure if he believed me but at the end of the day it's none of his business.
I've tried over the years to not be so ashamed and embarrassed about it, but it's not easy when you know most people will be horrified that you have the willpower to bring a blade to your skin.
tdlr; yes, many different people in my life have noticed and asked about my cutting scars. For most, it's none of their business. I only tell the truth about my scars to people I trust deeply, because I know they won't use it against me.