Rensselaer sits on Indiana 114 immediately west of I-65, the main north–south highway between Chicago and Indianapolis. Driving times are about 90 minutes from Chicago, two hours from Indianapolis, and an hour north from Lafayette.
Amtrak's Cardinal (Chicago–Cincinnati–New York City) stops at the unmanned Rensselaer station three times a week in each direction — one of the few small Indiana towns with a passenger rail service. Greyhound buses also stop in town on the Chicago–Indianapolis route.