Jennifer Lynn Armentrout (born June 11, 1980), also known by the pseudonym J. Lynn, is an American writer specializing in contemporary romance, new adult, and fantasy genres. Several of her works have made The New York Times Best Seller list.

She is considered a "hybrid" author, having successfully self-published while maintaining active contracts with small independent presses and traditional publishers. Her current publishers include Spencer Hill Press, Entangled Publishing, Harlequin Teen, Disney/Hyperion, and HarperCollins.

Jennifer lives in Charles Town, West Virginia. When she’s not writing, she spends her time reading, watching zombie movies, pretending to write, and hanging out with her husband and her Jack Russell named Loki.

In early 2015, Jennifer was diagnosed with retinitis pigmentosa, a group of rare genetic disorders that involve a breakdown and death of cells in the retina.