Hillenbrand's research in the area of star and planet formation, and the astrophysical processes associated with young stellar objects. She has over 250 refereed publications. Her observational and data analysis experience covers wavelengths from x-ray to millimeter, though focusing mostly on optical/near-infrared science. The most well-known research accomplishments include evidence for circumstellar disks around Herbig Ae/Be stars, determination of the stellar and sub-stellar initial mass function in the Orion Nebula Cluster, studies of age spreads in star forming regions, and determination of age constraints on circumstellar disk evolutionary timescales, both primordial and debris. Other research interests include star clusters, stellar angular momentum evolution, stellar age indicators, protostars, accretion and accretion-driven wind phenomena, young planets, variability phenomena in young stars, stellar multiplicity.