Acoustic　metamaterials　exhibit　exceptional　sound　absorption　capabilities.　This　study　introduces　a　fractal　labyrinthine　acoustic　metamaterial　(FLAM)　designed　for　sound　absorption　analyses　in　a　low-frequency　range　of　1–2000　Hz.　The　fractal　curve　is　constructed　through　side　substitution　on　an　isosceles　right　triangle,　which　is　chosen　as　the　spatial　recursive　substructure　due　to　its　self-similarity.　The　FLAM　model　is　then　developed.　With　the　thermal　viscous　losses　considered　in　narrow　channels,　the　sound　absorption　coefficient　of　this　model　is　theoretically　analyzed　as　the　structural　parameters　significantly　affect　the　sound　absorption.　A　comprehensive　analysis　of　low-frequency　sound　absorption　performance　is　conducted　for　the　first　three　orders,　and　the　reconstruction　of　the　structure　with　different　combinations　of　fractal　orders　is　examined　to　optimize　the　FLAM.　The　results　show　that　the　proposed　FLAM　achieves　nearly　perfect　absorption　in　the　50–400　Hz　range,　with　peak　absorption　coefficients　of　0.99,　0.95,　and　0.95　for　the　first　three　orders.　The　proposed　FLAMs　for　the　first　three　orders　have　total　thicknesses　of　0.032λ,　0.021λ,　and　0.019λ,　demonstrating　excellent　low-frequency　sound　absorption　at　deep　sub-wavelength　scales.　©　2024　Elsevier　Ltd