When can non-muslims visit the Kaaba?

Non-Muslims are not allowed to visit the Kaaba at any time. The Kaaba, located in the Masjid al-Haram (Grand Mosque) in Mecca, Saudi Arabia, is considered the holiest site in Islam, and access to Mecca itself is strictly restricted to Muslims.

This restriction is based on Islamic tradition and Saudi Arabian laws, which cite verses from the Qur'an (Surah At-Tawbah 9:28) that prohibit polytheists and non-believers from approaching the sacred mosque. As a result, non-Muslims are not allowed to enter the city of Mecca, including the Grand Mosque and the Kaaba.

However, non-Muslims can visit Medina, Islam's second holiest city, but access to the Prophet's Mosque (Al-Masjid an-Nabawi) is limited to Muslims in certain areas.

https://quran.com/at-tawbah/28

https://www.islamiclandmarks.com/makkah-other/can-non-muslims-go-to-mecca