Ruth Marianna Mosko was born in Denver, Colorado, to Polish-Jewish immigrants Jacob and Ida Moskowicz. She was the youngest of ten children and was sent to live with her older sister Sarah when she was six months old.

Ruth fell in love with Izzy Handler, an art student, and they married in 1938 in Denver. She encouraged her husband to use his middle name, Elliot, and they moved to California.

Ruth and Elliot Handler founded Mattel Creations with Harold Matson. The company initially produced picture frames and other items but soon shifted to toys.

Mattel signed a $500,000 contract to sponsor a 15-minute segment of Walt Disney's Mickey Mouse Club on the ABC television network. This move significantly boosted the company's visibility and sales.

Mattel introduced the Barbie doll, named after the Handlers' daughter Barbara. The doll was an instant hit and became a cultural icon, revolutionizing the toy industry.

Ruth Handler became the president of Mattel, a position she held until 1975. During her tenure, the company introduced Black dolls as part of the Barbie collection and supported Shindana Toys, a Black empowerment project.

Ruth Handler was diagnosed with breast cancer and underwent a mastectomy. This experience led her to develop a new passion for creating realistic breast prosthetics.

Ruth Handler resigned from Mattel amid investigations into fraudulent financial reports. She pleaded no contest to charges and was fined $57,000 and sentenced to 2,500 hours of community service.

Ruth Handler founded Ruthton Corp. to develop and manufacture breast prosthetics called 'Nearly Me.' She became an advocate for early detection of breast cancer and helped bring attention to the disease.

Ruth Handler sold Ruthton Corp. to a division of Kimberly-Clark, marking the end of her active involvement in the business.

Ruth Handler died in California from complications during surgery for colon cancer. She was 85 years old and left behind a legacy as a pioneering businesswoman and inventor.