//JS

$('.select2').select2({

    templateResult: function(e) {

        icon = $(e.element).attr('data-icon')

        val = e.element;

        if(val){

            val = `<i class="${icon}"></i> ${val.text}`;

        }

        return val;

    },

    escapeMarkup: function(m) {

        return m;

    }

});

​

//HTML

<select class="select2">

  <option value="1" data-icon="fa fa-users"> TEXTO </option>

</select>

//JS

$('.select2').select2({

    templateResult: function(e) {

        icon = $(e.element).attr('data-icon')

        val = e.element;

        if(val){

            val = `<i class="${icon}"></i> ${val.text}`;

        }

        return val;

    },

    escapeMarkup: function(m) {

        return m;

    }

});

​

//HTML

<select class="select2">

  <option value="1" data-icon="fa fa-users"> TEXTO </option>

</select>