Although　rare　earth　zirconates　(RE2Zr2O7)　have　garnered　attention　as　viable　candidates　for　thermal　barrier　coatings　(TBCs),　they　suffer　from　low　fracture　toughness　and　accelerated　calcium-magnesium-alumina-silicate　(CMAS)　melt　corrosion　at　high　service　temperatures,　which　impedes　their　practical　application.　In　this　work,　we　developed　a　series　of　REAlO3/RE2Zr2O7　(RE　=　La,　Nd,　Sm,　Eu,　Gd,　and　Dy)　composites　with　a　eutectic　composition　that　not　only　significantly　enhanced　the　fracture　toughness　by　more　than　40%　relative　to　that　of　RE2Zr2O7　but　also　exhibited　improved　resistance　to　CMAS　corrosion.　The　increase　in　toughness　arises　from　multiple　mechanisms,　such　as　ferroelastic　toughening,　fine-grain　strengthening,　and　residual　stress　toughening,　all　of　which　trigger　more　crack　defects　and　energy　consumption.　Additionally,　the　CMAS　penetration　depth　of　the　REAlO3/RE2Zr2O7　composites　is　approximately　36%　lower　than　that　of　RE2Zr2O7.　Al-O　constituents　in　composites　can　capture　CaO,　SiO2,　and　MgO　in　CMAS　melts　and　increase　their　viscosity,　resulting　in　enhanced　CMAS　corrosion　resistance.　The　thermophysical　properties　of　the　REAlO3/RE2Zr2O7　composites　were　also　investigated,　and　their　coefficient　of　thermal　expansion　and　thermal　conductivity　are　comparable　to　those　of　7-8　wt　%Y2O3　partially　stabilized　ZrO2　(YSZ),　indicating　their　potential　as　TBC　materials.