Can one see Scotland from the island of Ireland at any point?

The closest points between the two countries are only 12 miles (19 km) apart. The Straits of Moyle ("Sruth na Maoile" in Irish and Scottish Gaelic) is the narrowest expanse between north-eastern Northern Ireland (County Antrim) and south-western highlands of Scotland (Mull of Kintyre).

So yes - it is possible to see across in clear weather conditions.

https://vagabondtoursofireland.com/blog/ireland-and-scotland-tours

In addition to my first answer there is a map showing the two countries. The "O" of "North Channel" is where they almost meet.

https://en.wikipedia.org/wiki/North_Channel_(Great_Britain_and_Ireland)#/media/File:North_Channel.png

If you look for Mull of Kintyre on Google maps, click on one of the blue panorama dots, and face south-west, you can see the view of Ireland.

https://www.google.com/maps/place/Mull+of+Kintyre+Lighthouse/@55.3109042,-5.8184857,13z/data=!4m5!3m4!1s0x4861e19de27ef261:0x68eaf24d3a374d4d!8m


If you look for Torr Head, Ballycastle on Google maps, click on one of the blue panorama dots, and face north-east, you can see the view of Scotland.

https://www.google.com/maps/place/Torr+Head/@55.1959827,-6.0636059,21z/data=!4m5!3m4!1s0x4861dae4dca10415:0x4ef17c8222374f2e!8m2!3d55.1959827!4d-6.0634691