We present our latest results on the fabrication and properties of high‐TcNb3Sn thin‐film weak links and SQUID’s prepared by radiation damage of localized regions. Using radiation damage, we have successfully fabricated high‐temperature thin‐film weak links with current‐voltage characteristics similar to those produced either by proximity effect or ion‐implantation techniques. The critical current of these weak links obey a relationIc∝ (T′c‐T)3/2forT<T′c, andIc∝exp(−&ggr;T) forT≳T′c, whereT′cis the intrinsic transition temperature of the radiation‐damaged region. High‐temperature (operation temperature ≳14.5 K) Nb3Sn thin‐film SQUID’s with sensing area ∼3 mm2have been successfully fabricated using these weak links.