dialog?.window?.setBackgroundDrawable(ColorDrawable(Color.TRANSPARENT))
Example
class BusyDialogFragment: DialogFragment() { override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? { // return super.onCreateView(inflater, container, savedInstanceState) // make white background transparent dialog?.window?.setBackgroundDrawable(ColorDrawable(Color.TRANSPARENT)) return activity!!.layoutInflater.inflate(R.layout.busy, container) }}
NOTE: To remove dark overlay background, refer to Remove Dialog Black Overlay Background