The 1979–80 was the eighth season of Mersin İdmanyurdu (MİY) football team in Second League, the second level division in Turkey.

Mersin İdmanyurdu lost the second league championship game against Kocaelispor, the Group B's winner.

Mersin İdmanyurdu participated in 1979–80 Turkish Cup and was eliminated at round 3 by MKE Kırıkkalespor.

[12] The drawings and results Mersin İdmanyurdu (MİY) followed in 1979–80 Turkish Cup are shown in the following table.

Mersin İdmanyurdu (MİY) 1979–80 Turkish Cup game reports is shown in the following table.

Transfer news from Milliyet: MİY forward İbrahim ended his player career in the mid-season.