Can I connect a pen drive to my Samsung Galaxy S3 Mini using USB OTG? I am using Samsung Galaxy S3 Mini. Can I connect my phone with a pen drive using an on-the-go (OTG) USB cable?
I would assume, YES.

Currently, my Samsung Galaxy S4 (using the latest stock ROM) supports USB OTG.

Before that, I had a Samsung Galaxy S2. Using the stock ROM, I could not use USB OTG. So, I installed USB OTG Helper, which requires your phone to have root. When I changed to CyanogenMod (CM) ROM 10.1, I did not need USB OTG Helper; it had USB OTG support.