Electroless deposition of gold nanoparticles (Au-NPs) onto ion-irradiated single-wall carbon nanotubes (SWCNTs) represents a selective method to spatially profile defects by scanning electron microscopy (SEM). High purity SWCNT papers were irradiated with 150 keV 11B+ and subsequently exposed to 0.01 M KAuBr4(aq) to nucleate Au-NPs. Based on statistical image analysis, a 30 s KAuBr4(aq) exposure is sufficient to indicate the presence of defects by Au-NP nucleation, resulting in particle radii of ∼14 nm and minimal coalescence. A decrease in interparticle distance along individual SWCNT bundles and an increase in Au-NP areal density from 3 to 58 Au-NPs/μm2 are measured over the fluence range of 1 × 1013–1 × 1015/cm2, respectively. Raman analysis shows that the G′-band peak position progressively downshifts for the SWCNTs due to ion irradiation, whereas purified SWCNTs exhibit an upshift from charge transfer with KAuBr4(aq). A strong correlation between the Au-NP areal density from SEM and the relative ratios for the Raman D and G′ peaks confirms the method is directly monitoring ion irradiation-induced structural damage. Overall, the procedure provides a rapid assessment of SWCNT defect density based on microscopy analysis and shows that SWCNTs can be used as a fluence-based dosimeter or adequate support for controlled NP deposition.