It is inherited through the X-chromosome and is independent of other known susceptibility genes that women can already be tested for.
Experts say more studies are needed to confirm the identity and function of the gene.
The latest findings appear in the journal PLoS Genetics.
Currently, women with a strong family history of cancer can be tested for the BRCA gene, which greatly increases a woman's chance of developing breast cancer and ovarian cancer.
Angelina Jolie inherited BRCA1 from her mother - she had preventative surgery after her doctors estimated she had an 87% risk of breast cancer and a 50% risk of ovarian cancer.
But researchers believe there may be many other cases of seemingly sporadic ovarian cancer that are actually inherited - some via the X chromosome girls get from their father.
Men pass on one X chromosome to their daughters.
Dr Kevin Eng and colleagues at the Roswell Park Cancer Institute honed in on one suspect gene, called MAGEC3, located on the X chromosome from fathers.
Ovarian cancers linked to genes inherited from the father (and paternal grandmother) had an earlier age-of-onset than ones linked to maternal genes, and were also associated with higher rates of prostate cancer in fathers and sons.
Lead author Kevin Eng from the Roswell Park Comprehensive Cancer Centre in Buffalo, New York said: "What we have to do next is make sure we have the right gene by sequencing more families. This finding has sparked a lot of discussion within our group about how to find these X-linked families.
"It's an all-or-none kind of pattern: A family with three daughters who all have ovarian cancer is more likely to be driven by inherited X mutations than by BRCA mutations."