Harley sits at #62 in our pet rankings with 1,368 entries and a roughly even split between dogs and cats, male and female. The name lands as gender-neutral in a way most pet names do not — and the reason is split between two source images that almost never overlap. There is the motorcycle Harley, and there is Harley Quinn. Owners reach for one or the other and usually do not realize the other exists.
The motorcycle lineage
For owners over forty, Harley typically means Harley-Davidson. The name carries the same affectionate-tough register as Diesel, Mack, or Bandit. It tends to land on medium-to-large dogs in working or sporting groups, often on rescues where the original owner had a clear aesthetic. You will see Harley on Pit Bull mixes, on Labradors, on the kind of Heeler-cross that ends up at a Fourth of July cookout wearing a bandana.
This is the older Harley, and it skews male. Owners in this lineage rarely think of the name as gender-neutral; they think of it as a boys' name that happens to also work on female dogs. The crossover into German Shepherds and Labradors is well documented in the data.
The Harley Quinn pivot
The 2016 Suicide Squad film and the 2020 Birds of Prey spinoff pushed Harley sharply toward the female register for a younger generation of owners. Margot Robbie's version of the character — chaotic, blonde, in a baseball bat and roller skates — gave the name a completely different emotional shape. Owners under thirty-five who pick Harley for a female dog are usually working from this image, not from the motorcycle one. The name reads playful and slightly unhinged in the best way, and it tends to land on small mixes, French Bulldogs, and the occasional cat.
What's interesting is that the two readings have not collided. They occupy different owner demographics and rarely overlap at the same dog park. The data does not let me prove it, but the lived experience of running a Harley search on Petfinder will. You can usually tell within ten seconds which version of the name you are looking at.
The neutral middle
A smaller third group treats Harley as a genuinely unisex modern name, in the same family as Scout or Marley. These are owners who picked it because it sounded fresh and did not commit to either source. The human Harley sits in this register too — gently rising on the SSA charts as a girls' name, with a quieter male trail behind it. The pet name is roughly a decade ahead of where the baby name will be.