Carbon　aerogel　piezoresistive　sensors　(CAPSs),　owing　to　their　good　thermal　stability,　self-constructed　conductive　network,　and　fast　response　to　pressure,　have　attracted　extensive　attention　in　the　field　of　flexible　and　wearable　electronics　in　recent　years.　However,　it　is　still　a　great　challenge　for　CAPSs　to　monitor　subtle　deformations　and　achieve　high-performance　underwater　piezoresistive　sensing.　Herein,　a　superhydrophobic　and　electrically　conductive　carbon　aerogel　composite　(CAC)　was　fabricated　by　the　combination　of　fluorination　of　carbon　aerogels　and　decoration　of　fluorinated　halloysite　nanotubes　(HNTs).　Due　to　the　exceptional　light　absorption　and　excellent　photothermal　conversion　performance,　CAC　has　a　fast　and　accurate　response　to　temperature　with　a　high-temperature　coefficient　of　resistance　(TCR)　of　−1.06%/°C.　The　resistance　of　CAC　exhibits　a　linear　response　toward　compressive　strain　up　to　80%　with　a　high　gauge　factor　of　−1.24.　Significantly,　the　CAC　sensor　can　effectively　detect　tiny　deformations,　thanks　to　its　excellent　waterproof　performance,　and　it　enables　stable　output　of　sensing　signals　in　an　underwater　environment.　This　work　provides　new　insights　into　the　development　of　superhydrophobic,　multifunctional,　and　mechanically　durable　piezoresistive　sensors　with　potential　applications　in　underwater　flexible　electronics.　©　2024　American　Chemical　Society.