Ludden was born on October 5, 1917, in Mineral Point, Wisconsin, the first child of Elmer and Leila M. (née Allen) Ellsworth.

The family lived briefly in the Wisconsin cities of Janesville, Elkhorn, Antigo, and Waupaca before moving to Texas when Ludden was nine years old.

He served in the United States Army as officer in charge of entertainment in the Pacific theater, received a Bronze Star Medal for meritorious service, and was discharged with the rank of captain in 1946.

[11] Ludden began hosting an updated version of the game, Password Plus, on NBC, in 1979, but chemotherapy treatments for stomach cancer forced him off the show in late October 1980.

After Ludden was diagnosed with stomach cancer in early 1980, he took a month-long leave of absence from Password Plus for chemotherapy treatment, with Bill Cullen filling in as host.

[16] It was initially reported that he had a stroke, but the coma was actually caused by high levels of calcium from medication taken to help fight the cancer.

[7] Ludden was buried beside his father in the Ellsworth family plot in Graceland Cemetery in his hometown of Mineral Point, Wisconsin.

[17] Betty White also donated a Labrador Retriever named "Ludden" to Guide Dogs for the Blind in San Rafael, California, in memory of her late husband.

[23] The Allen Ludden Papers collection is located at the Free Public Library in his native Mineral Point, Wisconsin.