In this study, novel (Ti,Hf)(C,N) ceramics with varying hafnium contents were fabricated via carbothermal reduction–nitridation and subsequent spark plasma sintering. The influence of Hf addition on the mechanical properties, wear properties, and corrosion resistance of the (Ti,Hf)(C,N) ceramics was systematically studied. The introduction of Hf promoted the sintering densification of the ceramics in the sintering process. The prepared (Ti,Hf)(C,N) ceramics exhibited excellent mechanical and wear properties owing to refinement and solution-strengthening mechanisms. The (Ti0.9,Hf0.1)(C0.5,N0.5) ceramic demonstrated higher Vickers hardness and fracture toughness, measuring 1997 HV5 and 4.28 MPa m1/2, respectively, compared to the pure Ti(C0.5,N0.5) ceramic which exhibited values of 1635 HV5 and 3.94 MPa MPa m1/2. The wear scar depth of the (Ti0.9,Hf0.1)(C0.5,N0.5) ceramic sample was 57.36% to that of the Ti(C0.5,N0.5) ceramic. Additionally, the addition of Hf improved the corrosion resistance of (Ti,Hf)(C,N) ceramics in a 0.5 M NaOH solution. The potential applications of (Ti,Hf)(C,N) ceramics include machining tools and wear-resistant parts.