Mangano was born in 1956, in East Meadow, New York, to Italian-American parents. Mangano began inventing at an early age when, as a teenager working at an animal hospital in Huntington, New York, on Long Island, she dreamed up a fluorescent flea collar to keep pets safe. A product with a similar design was released the next year by Hartz Mountain. After graduating from Pace University with a degree in business administration in 1978, she held a variety of jobs, including waitress and airline reservations manager while raising her three children as a divorced mother.
Mangano holds more than 100 patents for her inventions. "I think my products have been successful because they have mass appeal," she has said. "I'm just like everybody else out there. I'm a mom, I work, I have a house to clean, things to organize. We all have similar needs, and I address them."
In 1990 after growing frustrated with ordinary mops, Mangano developed her first invention, the Miracle Mop, a self-wringing plastic mop with a head made from a continuous loop of 300 feet (90 meters) of cotton that can be easily wrung out without getting the user's hands wet. With her own savings and investments from family and friends, she made a prototype and manufactured 100 units. Early assembly was done in her father's body shop in Deer Park in 1991.
After selling the mop at trade shows and in local stores on Long Island, she sold 1,000 units on consignment to QVC. It sold modestly at first, but once QVC allowed Mangano to go on-air to sell it herself, she sold 18,000 mops in less than a half hour. Mangano incorporated her business as Arma Products, later renaming it Ingenious Designs. She sold Ingenious Designs to USA Networks, the parent company of the Home Shopping Network, in 1999. By the year 2000, her company was selling $10 million worth of Miracle Mops per year.
Huggable Hangers – velvet-flocked, no-slip hangers whose thin profile conserves closet space. Endorsed by Oprah Winfrey, Huggable Hangers were HSN's best-selling product as of 2010, with more than 300 million sold.
Forever Fragrant – a line of home odor neutralizers including sticks, wickless candles, scent stands, finials, spheres, drawer liners, and shoe shapers. Mangano broke an HSN record on January 31, 2010 by selling 180,000 units in one day. The Forever Fragrant line has won the Good Housekeeping Seal of Approval.
Clothes It All Luggage System – wheeled luggage with organizational features like a padded laptop compartment, a toiletry organizer, a pocket for plane tickets, and removable dividers. They range from smaller duffel bags to a 22-inch (56-centimeter) portable dresser with removable drawers, as well as a briefcase and pet carrier.
Performance Platforms – shoes with a rubber platform heel that gives the wearer extra height. In May 2010, Mangano sold 30,000 pairs in three hours on HSN. The line began as sneakers, and has since branched to Mary Janes, mules, and sandals. The shoes are produced in conjunction with the Grasshoppers division of the Stride Rite Corporation.
Comfort & Joy Textiles – bedding made from Supima cotton and down alternative with a reversible, zippered duvet cover and sheets that are attached to the bed skirt for removal and cleaning.
Shades Readers – a line of reading glasses sold in sets of three or more so that they can be kept around the home and office for easy access. Mangano has sold more than a million pairs.
Soon after she began appearing on QVC in 1992, Mangano began spending 120 hours a year on air. She now appears regularly on HSN, and is considered to be HSN's most successful purveyor, with annual sales of more than $150 million. Her hourly sales regularly top $1 million. Mangano has also appeared in shorter commercials and infomercials for her company's products. She said that while selling on television is an opportunity to reach millions of people, it requires genuine enthusiasm to persuade people who can't touch or try the product. An HSN executive wrote that Mangano's success is due to her ability to convey her "passion, excitement and pride of every detail with her viewers."
In 2005, Mangano was a judge on the cable reality show Made in the USA. She also appeared on the ABC show The View on February 2, 2007.
Mangano has partnered with celebrities and other television personalities to bring their products to HSN. They include tennis star Serena Williams' line of jewelry, Frank Sepe fitness products, fashions from supermodel Iman, products from Rosie O'Donnell, Esteban guitars, and Who Knew? books by Bruce Lubin. She also partnered with chef Todd English to create GreenPan cookware, which uses a ceramic-based non-stick coating that the press release describes as: "PTFE-free, and uses no PFOA in manufacturing, making GreenPan cookware 'green' in manufacturing". Mangano and English debuted GreenPans on HSN on July 26, 2007, and sold 24,000 pieces in 4 hours.
In 1997, Mangano was named Long Island Entrepreneur of the Year by Ernst & Young. In 2009, she was ranked number 77 on Fast Company's list of The 100 Most Creative People in Business; and in 2010, she was listed in their list of The 10 Most Creative Women in Business.
A character based on Mangano is portrayed by Jennifer Lawrence in the 2015 film Joy, directed by David O. Russell, with Mangano credited as executive producer. It was released on Christmas Day 2015.
Mangano married Tony Miranne in 1978 shortly after both graduated from Pace University. They divorced in 1989. They have three children: Christie, Robert, and Jacqueline Miranne.