Upvote:7
If you are traveling alone, being a resident in Greece doesn't exempt you from any visa requirement in Ireland. To the extent that a visa is required for your specific circumstances (citizenship, purpose and length of the trip), you will need to obtain one regardless. South African citizens do need a visa, even for a short tourism visit.
Since you mention your spouse, I suspect you might reside in Greece as the spouse of an EU (Irish?) citizen. If you have a residence card as a member of an Union Citizen's family (it should say so on the card) and you are traveling with them or joining them, you would indeed be exempted from any visa requirement. Since you are traveling without your spouse, this exemption doesn't apply here.