Jeanne Robertson, who turned her title of Miss Congeniality at the 1963 Miss America pageant into a career as a public speaker and who later found success as a squeaky clean humorist with a sizable YouTube following, died on Aug. 21 at her home in Burlington, N.C. She was 77.

The cause was unknown, her son, Bailey Bowline, said.

Her comedic videos on YouTube, where she had more than 340,000 followers, and stints on SiriusXM’s comedy channels made Ms. Robertson a beloved figure in family-friendly comedy. She also appeared in live shows around the country, playing civic auditoriums, churches and theaters, including the Grand Ole Opry.

Ms. Robertson, whose first name was pronounced Jeannie, called herself a humorist, not a comic or a comedian, because, she said, she focused on telling stories rather than just doing bits for laughs.

She maintained her pageant polish in speaking appearances; she did not swear or make crude jokes, favoring instead details of everyday life and anecdotes about her family and friends. Much of her material centered on her husband, Jerry Robertson, whom she affectionately called Left Brain, homage to his logical and process-driven way of thinking.

She talked about her son, nicknamed Beaver, being grounded for misbehavior and about encountering broken escalators at the Philadelphia International Airport, and she poked fun at her own Southern accent. Her stories had titles like “Don’t Bungee Jump Naked” and “Mothers vs. Teenage Daughters.”

Ms. Robertson posted her most popular YouTube video in 2009; it’s a Left Brain story called “Don’t Send a Man to the Grocery Store,” and 12 years later it had registered more than 16 million views. In the video she recounts writing out a shopping list for her husband and numbering the items needed. He took the task literally, thinking that the numbers were quantities, and brought home 25 pounds of sugar and enough flour to fill a storeroom.

After the video’s success, demand for Ms. Robertson as a humorist rose, and she worked with Al McCree, a speaker and musician from Nashville, who became her manager after they met at a National Speakers Association event. Touring soon became a large part of her professional life. At her death, she had more than 50 future shows booked, Mr. McCree said.

Ms. Robertson’s humor played well at corporate banquets and with crowds who eschewed edgy jokes for wholesome entertainment and who were drawn to her graceful demeanor, Southern drawl and clean humor. Recordings of her speaking aired on SiriusXM’s Laugh USA and Blue Collar Comedy channels.

Jeanne Flinn Swanner, one of three sisters, was born on Sept. 21, 1943, in Boston to Jim and Cora (Lipscomb) Swanner. She grew up in Graham, N.C., and lived in the state for most of her life. Her father was a captain in the Marines during World War II and a former engineering professor who later ran a gas company. Her mother was a homemaker and helped run the company.

Jeanne attended Graham High School and then Auburn University.

She began entering pageants, and winning a few, in college, becoming Miss North Carolina in 1963. At 6-foot-2, she often joked about her height and said she was the tallest Miss America contestant ever. At the Miss America pageant in Atlantic City, other contestants and administrators praised her backstage humor and onstage grace, making her a natural for Miss Congeniality.

“People started talking about how funny I was, and people wanted to hear me speak,” Ms. Robertson told The Sentinel of Carlisle, Pa., in 2011. “That year I had to drop out of school because there was so much. I gave over 500 presentations that year.” Most were related to her role as Miss North Carolina.

She returned to Auburn and graduated in 1967 with a bachelor’s degree in physical education. She taught physical education at high schools for nearly a decade and gave speaking engagements on weekends, often with her son in tow. She then began speaking full-time at conferences, for government organizations and at pageants, where she was a popular M.C.

She married Walter Bailey Bowline III in 1965, when they were both students at Auburn. The marriage ended in divorce in the early 1970s. She married Mr. Robertson in 1974. He died in June.

In addition to her son, Mr. Bowline, she is survived by two grandsons and her sister Katherine Swanner.

She was a trustee at Elon University in North Carolina and active in groups like the National Speakers Association, which gave her the Cavett Award, its highest honor.

Ms. Robertson had a sense of purpose when it came to telling funny stories. As her son said, “She felt like, if people would take themselves less seriously and the world around them less seriously, everything would be a lot better.”