Soil microbial diversity is expected to be altered by the establishment of invasive plant species, such as dog-strangling vine (DSV) [Vincetoxicum rossicum (Apocynaceae)]. However, in urban ecosystems where DSV invasion is high, there is little research evaluating the impacts of DSV and other anthropogenic disturbances on microbial diversity. Our study was based in Rouge National Urban Park, Canada, where we used terminal restriction fragment length polymorphism data to evaluate (i) if DSV has a detectable impact on soil bacterial community composition and (ii) if these impacts occur independently of other anthropogenic change or soil characteristics. Variation in soil bacterial communities was greatly reduced in DSV-invaded sites vs. less-invaded sites. The degree of DSV invasion independently explained 23.8% of variation in bacterial community composition: a value similar to the explanatory power of proximity to roadways (which explained 22.6% of the variation in community composition), and considerably greater than soil parameters (pH, moisture, carbon, and nitrogen concentrations) which explained only between 6.0% and 10.0% of variation in bacterial community composition. Our findings indicate that DSV influences soil bacterial community composition independent of other anthropogenic disturbances and soil parameters, with potential impacts on multiple facets of plant–soil interactions and plant invasion dynamics.