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<p>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 10<span class="inline-formula">^∘</span> 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 TEX<span class="inline-formula">₈₆</span> and <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M3" display="inline" overflow="scroll" dspmath="mathml"><mrow><msubsup><mi>U</mi><mn mathvariant="normal">37</mn><mrow><msup><mi>k</mi><mo>′</mo></msup></mrow></msubsup></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="18pt" height="18pt" class="svg-formula" dspmath="mathimg" md5hash="5ec84048506428000d5895a3709a326f"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cp-19-787-2023-ie00001.svg" width="18pt" height="18pt" src="cp-19-787-2023-ie00001.png"/></svg:svg></span></span> as two independent quantitative proxies. Both proxies indicate that Site 1168 experienced a temperate <span class="inline-formula">∼</span> 25 <span class="inline-formula">^∘</span>C during the early Miocene (23–17 Ma), reaching <span class="inline-formula">∼</span> 29 <span class="inline-formula">^∘</span>C during the mid-Miocene climatic optimum. The stepwise <span class="inline-formula">∼</span> 10 <span class="inline-formula">^∘</span>C cooling (20–10 <span class="inline-formula">^∘</span>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 <span class="inline-formula">∼</span> 15 <span class="inline-formula">^∘</span>C (3 Ma), then decreases to <span class="inline-formula">∼</span> 6 <span class="inline-formula">^∘</span>C (1.3 Ma), and eventually increases to the modern levels around <span class="inline-formula">∼</span> 16 <span class="inline-formula">^∘</span>C (0 Ma), with a higher variability of 5<span class="inline-formula">^∘</span> 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 <span class="inline-formula">^∘</span>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.</p>