Tracy McMillan (born September 12, 1964) is an American author, television writer, TV host, and self-proclaimed relationship expert. She wrote television news for 15 years and transitioned into writing film, television, and books.

In 2011, she wrote a blog post called WHY YOU’RE NOT MARRIED, which went viral and is now the most-viewed article on the Huffington Post ever. Time magazine named it one of the Top Ten Opinion Pieces of 2011.  She also wrote a book based on it, Why You're Not Married... Yet (2012).

Her screenwriting credits include Mad Men, Necessary Roughness, Chase, Life on Mars, and The United States of Tara. She won the 2010 Writers Guild of America Awards for Dramatic Series for Mad Men, along with other writers of the series.

As a relationship expert, she's made numerous television and radio appearances, including as a matchmaker on the NBC dating reality show Ready for Love, as well as The Today Show, Katie, Bethenny, Dr. Drew's Lifechangers, and Oprah's Super Soul Sunday. She is the relationship expert on the OWN channel's Family or Fiancé (2020- ).

She is the author of a memoir, I Love You and I'm Leaving You Anyway (2010) and her debut novel, You'll Know It When You See It (2015). She continues to write occasionally for the Huffington Post.