Levitt was born Elizabeth Levi in Hackney, London, to a prosperous Jewish family of Sephardi descent. Around 1902 she was employed as a secretary at the Napier & Son engineering works in Lambeth, where she came to the attention of Selwyn Edge, the company's racing driver and British agent. Edge had observed how French driver Camille du Gast's participation in races generated press coverage and sought a British equivalent. He promoted Levitt to personal assistant and arranged six months of automobile apprenticeship training in Paris, where she learned construction, mechanics, and driving. Edge also provided her cars and motorboats for competition and promotional purposes; she is presumed to have been his mistress for a time.
Levitt made her competitive debut in April 1903 as the first English woman ever to enter a motor race. At the Southport Speed Trials in October 1903 she won her class in a Gladiator — the first British woman to take part in a speed competition. In 1905 she established the record for the longest drive by a lady driver, completing a London–Liverpool round trip in a De Dion-Bouton over two days, averaging 20 mph for 411 miles without a mechanic.
At the inaugural Brighton Speed Trials in July 1905 she set her first Ladies' World Speed Record, driving an 80 hp Napier at 79.75 mph. In October 1906 at the Blackpool Speed Trials she broke her own record, achieving 90.88 mph in a 100 hp Napier K5-L48 over a flying kilometre, earning the press sobriquets the "Fastest Girl on Earth" and the "Champion Lady Motorist of the World." At Shelsley Walsh in 1906 she set the Ladies' Record in the Open Class with a time 12 seconds faster than the male winner, a record that stood until 1913.
In 1907 and 1908 she competed successfully in Germany and France, winning a gold medal at the Herkomer Trophy Race in Germany among 172 competitors, finishing fourth overall and first among all women. She also began competing at Brooklands after it relaxed its ban on women drivers in 1908.
In July 1903 Levitt won the inaugural British International Harmsworth Trophy for motor-boats at Cork Harbour in Ireland, defeating the French entry. In doing so she set the world's first Water Speed Record, achieving 19.3 mph in a 40-foot, 75-horsepower Napier speedboat. She was subsequently commanded aboard the Royal yacht by King Edward VII, who congratulated her on her skill. Later that summer she won the Gaston Menier Cup at Trouville, France, a race billed as the five-mile world championship of the sea.
Levitt was a forceful advocate for women's right to drive. She taught Queen Alexandra, the Royal Princesses (Louise, Victoria, and Maud), and numerous other women to drive. Her 1909 book The Woman and the Car: A Chatty Little Handbook for all Women who Motor or Who Want to Motor grew from her newspaper column in The Graphic. The book famously advised women to carry a small hand-mirror to see traffic behind them while driving — a precursor to the rearview mirror — and recommended that women travelling alone carry a handgun for self-defence. She also ran a motoring column in the Yorkshire Evening Post. She was among the first women to attempt an aviation qualification, attending Hubert Latham's flying school in France in 1909.
Levitt's public career ended abruptly after 1910, and her life thereafter went largely undocumented. She was found dead in her bed at 50 Upper Baker Street, Marylebone, on 17 May 1922. The death certificate listed the cause as morphine poisoning while suffering from heart disease and measles; the inquest returned a verdict of misadventure. She was unmarried; her estate of £224 passed to her sister Elsie. A Blue Plaque now marks her birthplace on Colvestone Crescent in recognition of her pioneering sporting achievements.