The Neogene (23.04–2.58 Ma) is characterised by progressive buildup of ice volume and climate cooling in the Antarctic and the Northern Hemisphere. Heat and moisture delivery to Antarctica is, to a large extent, regulated by the strength of meridional temperature gradients. However, the evolution of the Southern Ocean frontal systems remains scarcely studied in the Neogene. Here, we present the first long-term continuous sea surface temperature (SST) record of the subtropical front area in the Southern Ocean at Ocean Drilling Program (ODP) Site 1168 off western Tasmania. This site is, at present, located near the subtropical front (STF), as it was during the Neogene, despite a 10inline-formula^∘ northward tectonic drift of Tasmania. We analysed glycerol dialkyl glycerol tetraethers (GDGTs – on 433 samples) and alkenones (on 163 samples) and reconstructed the paleotemperature evolution using TEXinline-formula₈₆ and inline-formula $M3inlinescrollmathml{U}_{\mathrm{normal\; 37}}^{k^{\prime }}$ 18pt18ptsvg-formulamathimg5ec84048506428000d5895a3709a326f cp-19-787-2023-ie00001.svg18pt18ptcp-19-787-2023-ie00001.png as two independent quantitative proxies. Both proxies indicate that Site 1168 experienced a temperate inline-formula∼ 25 inline-formula^∘C during the early Miocene (23–17 Ma), reaching inline-formula∼ 29 inline-formula^∘C during the mid-Miocene climatic optimum. The stepwise inline-formula∼ 10 inline-formula^∘C cooling (20–10 inline-formula^∘C) in the mid-to-late Miocene (12.5–5.0 Ma) is larger than that observed in records from lower and higher latitudes. From the Pliocene to modern (5.3–0 Ma), STF SST first plateaus at inline-formula∼ 15 inline-formula^∘C (3 Ma), then decreases to inline-formula∼ 6 inline-formula^∘C (1.3 Ma), and eventually increases to the modern levels around inline-formula∼ 16 inline-formula^∘C (0 Ma), with a higher variability of 5inline-formula^∘ compared to the Miocene. Our results imply that the latitudinal temperature gradient between the Pacific Equator and the STF during late Miocene cooling increased from 4 to 14 inline-formula^∘C. Meanwhile, the SST gradient between the STF and the Antarctic margin decreased due to amplified STF cooling compared to the Antarctic margin. This implies a narrowing SST gradient in the Neogene, with contraction of warm SSTs and northward expansion of subpolar conditions.