It might be possible to disable Bixby entirely on your Samsung phone, depending upon which model you own.

Google Assistant is available on many devices, including phones, tablets, and Chromebooks. It's useful, but the virtual assistant's notifications and pop-up windows can clutter up your device's screen ...

Google Assistant comes pre-installed on all Android phones and is helpful in various ways, but if you don't use it often, you can disable it on your device. I'll show you exactly how to do that.

Google Assistant can work on the lock screen, and anyone can access your phone. That's why you should disable Google Assistant on the lock screen.