One of six children of a dry goods salesman and a free-thinking mother, Emily Hahn was born in St. Louis Missouri on January 14, 1905. Nicknamed "Mickey", she moved with her family to Chicago, Illinois when she was 15. In her memoir No Hurry to Get Home, she describes how being prevented from taking a chemistry class in which she was interested caused her to switch her course of study from English to Engineering at the University of Wisconsin—Madison. In 1926 she was the first women to receive a degree there in Mining Engineering—despite the coolness of the administration and most of her male classmates. It was a testament to her intelligence and persistence that her lab partner grudgingly admitted, "you ain't so dumb!"

After graduation she worked briefly for an engineering company in Illinois, before traveling across the United States by car with a female friend, both disguised as men, and then working as a "Harvey Girl" tour guide in New Mexico. Later she traveled to the Belgian Congo, where she worked for the Red Cross, and lived with a pygmy tribe for two years, before crossing Central Africa alone on foot.

Her first book, Seductio ad Absurdum: The Principles and Practices of Seduction--A Beginner's Handbook (1930), was a tongue-in-cheek exploration of how men court women.

Her years in Shanghai, China (from 1935 to the Japanese invasion of Hong Kong in 1941) were the most tumultuous of her life. There she became involved with prominent Shanghai figures, such as the wealthy Sir Victor Sassoon, and was in the habit of taking her pet gibbon, Mr. Mills, with her to dinner parties, dressed in a diaper and a minute dinner jacket.

Supporting herself as a writer for The New Yorker, she lived in an apartment in Shanghai's red light district, and became romantically involved with the Chinese poet and publisher Sinmay Zau (). He gave her the entrée that enabled her to write a biography of the famous Soong sisters, one of whom was married to Sun Yat-sen and another to Chiang Kai-shek.

Hahn frequently visited Sinmay's house, which was highly unconventional for a Western woman in the 1930s. The Treaty of the Bogue was in full effect, and Shanghai was a city divided by Chinese and Westerners at the time. Sinmay introduced her to the practice of smoking opium, to which she became addicted. She later wrote, "Though I had always wanted to be an opium addict, I can't claim that as the reason I went to China."

After moving to Hong Kong, she began an affair with Charles Boxer, the local head of British army intelligence. According to a December 1944 Time article, Hahn "decided that she needed the steadying influence of a baby, but doubted if she could have one. 'Nonsense!' said the unhappily-married Major Charles Boxer, 'I'll let you have one!' Carola Militia Boxer was born in Hong Kong on October 17, 1941".

When the Japanese marched into Hong Kong a few weeks later Boxer was imprisoned in a POW camp, and Hahn was brought in for questioning. "Why?" screamed the Japanese Chief of Gendarmes, "why ... you have baby with Major Boxer?" "Because I'm a bad girl," she quipped. Fortunately for her, the Japanese respected Boxer's record of wily diplomacy.

As Hahn recounted in her book China to Me (1944), she was forced to give Japanese officials English lessons in return for food, and once slapped the Japanese Chief of Intelligence in the face. He came back to see her the day before she was repatriated in 1943 and slapped her back.

China to Me was an instant hit with the public. According to Roger Angell of The New Yorker, Hahn "was, in truth, something rare: a woman deeply, almost domestically, at home in the world. Driven by curiosity and energy, she went there and did that, and then wrote about it without fuss."

In 1945 she married Boxer who, during the time he was interned by the Japanese, had been reported by American news media to have been beheaded; their reunion—whose love story had been reported faithfully in Hahn's published letters—made headlines throughout the United States. They settled in Dorset, England at "Conygar", the estate Boxer had inherited, and in 1948 had a second daughter, Amanda Boxer (now a stage and television actress in London).

Finding family life too constraining, however, in 1950 Hahn took an apartment in New York City, and visited her husband and children from time to time in England. She continued to write articles for The New Yorker, as well as biographies of Aphra Behn, James Brooke, Fanny Burney, Chiang Kai-Shek, D. H. Lawrence and Mabel Dodge Luhan. According to biographer Ken Cuthbertson, while her books were favorably reviewed, "her versatility, which enabled her to write authoritatively on almost any subject, befuddled her publishers who seemed at a loss as to how to promote or market an Emily Hahn book. She did not fit into any of the usual categories" because she "moved effortlessly ... from genre to genre."

In 1978 she published Look Who's Talking, which dealt with the controversial subject of animal-human communication (her personal favorite among her non-fiction books); she wrote her last book Eve and the Apes in 1988 when she was in her eighties.

Hahn reportedly went into her office at The New Yorker daily, until just a few months before she died on February 18, 1997 at the age of 92, following complications from surgery for a shattered femur.

"Chances are, your grandmother didn't smoke cigars and let you hold wild role-playing parties in her apartment", said her granddaughter Alfia Vecchio Wallace in her affectionate eulogy of Hahn. "Chances are that she didn't teach you Swahili obscenities. Chances are that when she took you to the zoo, she didn't start whooping passionately at the top her lungs as you passed the gibbon cage. Sadly for you ... your grandmother was not Emily Hahn."

In 1998, Canadian author Ken Cuthbertson published the biography Nobody Said Not to Go: The Life, Loves, and Adventures of Emily Hahn. "Nobody said not to go" was one of her characteristic phrases.

In 2005 Xiang Meili (the name given to Hahn by Sinmay) was published in China. It looks back at the life and loves of Hahn in the Shanghai of the 1930s.

• Seductio ad Absurdum: The Principles and Practices of Seduction...A Beginner's Handbook (1930)
• Beginner's Luck (1931)
• Congo Solo: Misadventures Two Degree North (1933)
• With Naked Foot (1934)
• Affair (1935)
• Steps of the Sun (1940)
• The Soong Sisters (1941, 1970)
• Mr. Pan (1942)
• China to Me: A Partial Autobiography (1944, 1975, 1988)
• Hong Kong Holiday (1946)
• China: A to Z (1946)
• The Picture Story of China (1946)
• Raffles of Singapore (1946)
• Miss Jill (1947) also as House in Shanghai (1958)
• England to Me (1949)
• A Degree of Prudery: A Biography of Fanny Burney (1950)
• Purple Passage: A Novel About a Lady Both Famous and Fantastic (1950) (published in the UK as Aphra Behn (1951))
• Francie (1951)
• Love Conquers Nothing: A Glandular History of Civilization (1952)
• Francie Again (1953)
• Mary, Queen of Scots (1953)
• James Brooke of Sarawak: A Biography of Sir James Brooke (1953)
• Meet the British (with Charles Roetter and Harford Thomas) (1953)
• The First Book of India (1955)
• Chiang Kai-shek: An Unauthorized Biography (1955)
• Francie Comes Home (1956)
• Spousery (1956)
• Diamond: The Spectacular Story of the Earth's Greatest Treasure and Man's Greatest Greed (1956)
• Leonardo da Vinci (1956)
• Kissing Cousins (1958)
• The Tiger House Party: The Last Days of the Maharajas (1959)
• Aboab: First Rabbi of the Americas (1959)
• Around the World With Nellie Bly (1959)
• June Finds a Way (1960)
• China Only Yesterday, 1850-1950: A Century of Change (1963)
• Indo (1963)
• Africa to Me (1964)
• Romantic Rebels: An Informal History of Bohemianism in America (1967)
• Animal Gardens (1967)
• The Cooking of China (1968)
• Recipes: Chinese Cooking (1968)
• Times and Places (1970, reissued as No Hurry to Get Home 2000)
• Breath of God: A Book About Angels, Demons, Familiars, Elementals and Spirits (1971)
• Fractured Emerald: Ireland (1971)
• On the Side of the Apes: A New look at the Primates, the Men Who Study Them and What They Have Learned (1971)
• Once Upon A Pedestal (1974)
• Lorenzo: D. H. Lawrence and the Women Who Loved Him (1975)
• Mabel: A Biography of Mabel Dodge Luhan (1977)
• Look Who's Talking! New Discoveries in Animal Communications (1978)
• Love of Gold (1980)
• The Islands: America's Imperial Adventures in the Philippines (1981)
• Eve and the Apes (1988)

Emily Hahn