Lang Lang was born in Shenyang, China, and he has Manchu ancestry. At the age of two he watched the Tom and Jerry episode The Cat Concerto which features the Hungarian Rhapsody No. 2 by Franz Liszt. According to Lang Lang, this first contact with Western music is what motivated him to learn piano. He began lessons with Professor Zhu Ya-Fen at age three. At the age of five, Lang won first place at the Shenyang Piano Competition and performed his first public recital.

When he was nine years old, Lang Lang neared his audition for Beijing's Central Conservatory of Music, and, having difficulties with his lessons, was expelled from his piano tutor's studio for lack of talent. It was at this point, that his relationship with his father began to suffer. To avoid shame, his father claimed that "dying was the only way out" and ordered Lang Lang to commit suicide by urging him to swallow an entire bottle of antibiotics. His music teacher at his state school noticed Lang Lang's sadness, and decided to comfort him by playing a record of Mozart's Piano Sonata No. 10 in C Major, K. 330; she asked him to play along with the second movement. This reminded Lang Lang of his love of the instrument. "Playing the K. 330 brought me hope again," recalled Lang Lang.

Lang was later admitted into the conservatory under the study of Professor Zhao Ping-Guo. In 1993, Lang won the Xing Hai Cup Piano Competition in Beijing and was awarded first prize for outstanding artistic performance at the fourth International Competition for Young Pianists in Ettlingen, Germany, the next year. In 1995, at 13 years of age, he played the Op. 10 and Op. 25 études by Chopin at the Beijing Concert Hall and, in the same year, won first place at the International Tchaikovsky Competition for Young Musicians in Japan, playing Chopin's Piano Concerto No. 2 with the Moscow Philharmonic Orchestra in a concert broadcast by NHK Television. At 14 he was a featured soloist at the China National Symphony's inaugural concert, which was broadcast by China Central Television and attended by President Jiang Zemin. The following year he began studies with Gary Graffman and Dick Doran at the Curtis Institute of Music in Philadelphia.

Lang Lang has given sold out recitals and concerts in many major cities and is the first Chinese pianist to be engaged by the Berlin Philharmonic, the Vienna Philharmonic and the top American orchestras. A Chicago Tribune music critic called him "the biggest, most exciting young keyboard talent I have encountered in many a year of attending piano recitals". Lang Lang has garnered praise from musicians and critics around the world — the conductor Jahja Ling remarked, "Lang Lang is special because of his total mastery of the piano... He has the flair and great communicative power." National Public Radio's Morning Edition remarked that "Lang Lang has conquered the classical world with dazzling technique and charisma." It is often noted that Lang Lang successfully straddles two worlds — classical prodigy and rock-like "superstar", a phenomenon summed up by The Times journalist Emma Pomfret, who wrote, "I can think of no other classical artist who has achieved Lang Lang's broad appeal without dumbing down."

Lang Lang's performances have also been criticized. His performance style has been referred to as having "soggy rhythms and heavy phrasing," and as being "truly boring", "just bad" and "unendurable". Critics who feel that his playing is vulgar and lacks sensitivity have given him the nickname "Bang Bang". Pianist Earl Wild has called him “the J. Lo of the piano." Others have described him as immature, though praised his ability to "conquer crowds with youthful bravado". Conversely, the same style has led his performance to be described as one of "blazing speed and thunderous power... Lang's daredevil tendencies found a gratifying outlet." Some critics have argued that Lang is at his best playing the Classical repertoire as opposed to Romantic composers such as Chopin. However, his growth in recent years has also been noted in The New Yorker: "the ebullient Lang Lang is maturing as an artist."

Lang Lang is well known for his exaggerated gestures and facial expressions while playing piano, which has affected his recent performances, such as that of Liszt's Hungarian Rhapsody No. 2 in C-sharp Minor and Réminiscences de Don Juan. This has received criticism, though others have defended his displays, arguing "[Lang's] interpretations aren't just expressions of feeling but the feelings themselves." His "kinetic display" has also been described as "fun to watch", because "underneath the gymnastics, there's clearly some serious musical thinking going on."

In 2001, he made his sold-out Carnegie Hall debut with Yuri Temirkanov, travelled to Beijing with the Philadelphia Orchestra on a tour celebrating its 100th anniversary, during which he performed to an audience of 8,000 at the Great Hall of the People, and made an acclaimed BBC Proms debut, prompting a music critic of the British newspaper The Times to write, "Lang Lang took a sold-out Royal Albert Hall by storm... This could well be history in the making". In 2003, he returned to the BBC Proms for the First Night concert with Leonard Slatkin. After his recital debut in the Berlin Philharmonic, the Berliner Zeitung wrote: "Lang Lang is a superb musical performer whose artistic touch is always in service of the music".

Lang Lang is a featured soloist on the Golden Globe winning score of The Painted Veil and can be heard on the soundtrack of The Banquet. Lang Lang has recorded for the Deutsche Grammophon and Telarc labels.. His album of the first and fourth Beethoven piano concertos with the Orchestre de Paris and Christoph Eschenbach debuted at #1 on the Classical Billboard Chart. In 2010, he signed with Sony for a reported $3 million.

Lang Lang was the pianist on Mike Oldfield's 2008 album Music of the Spheres.

Lang Lang has performed for numerous international dignitaries including the former Secretary-General of the United Nations Kofi Annan, President Barack Obama, Queen Elizabeth II, President Hu Jintao of China, President Horst Köhler of Germany, Prince Charles, as well as Russian Prime Minister Vladimir Putin and French President Nicolas Sarkozy.

To date, tens of thousands of people have seen Lang Lang’s performances in open-air concerts in parks and venues, including New York City’s Central Park, Hollywood Bowl in Los Angeles, suburban Chicago’s Ravinia Festival, Theaterplatz in Dresden and Hamburg’s Derby Park.

In July 2007, Lang Lang was featured at the second concert from the Teatro del Silenzio, Lajatico, Italy, hosted by Andrea Bocelli. During this concert he performed "Io ci sarò" with Bocelli, and Liszt's "Hungarian Rhapsody". The performance is available on the DVD entitled "Vivere Live in Tuscany".

In December 2007, Lang Lang was guest soloist at the Nobel Prize concert in Stockholm, an event attended by the Nobel Laureates and members of the Royal Family. Collaborating with Maestro Seiji Ozawa, he appeared at the New Year’s Eve gala opening for the National Center for the Performing Arts in Beijing. He participated in the opening concert at Munich's Olympic Stadium with Mariss Jansons, marking the commencement of the World Cup and in a celebratory concert for the closing of ’08 Euro Cup finals Lang Lang played with the Vienna Philharmonic under the baton of Zubin Mehta in front of Schönbrunn Palace.

In 2008, over 5 billion people viewed Lang Lang’s performance in Beijing’s opening ceremony for the 2008 Summer Olympics where he was promoted as a symbol of the youth and future of China. During these games, he was also featured as a cultural correspondent on the German TV station ZDF and made several special appearances on NBC's The Today Show Summer Olympics broadcasts. In the opening ceremony he performed a melody from the Yellow River Cantata with seven-year-old Li Muzi.

In February 2008, Lang Lang and jazz pianist Herbie Hancock performed together at the 2008 Grammy Awards, playing George Gershwin's Rhapsody in Blue. The two were again brought in by United Airlines for the reintroduction of their "It's Time to Fly" advertising campaign with a series of new animated commercials, aired during the 2008 Summer Olympics. In April 2008, he premiered Tan Dun's First Piano Concerto, subtitled "The Fire". Herbie Hancock and Lang Lang will continue to collaborate with an inaugural world tour in summer 2009. He played at the 2009 Nobel Peace Prize ceremony for US President Barack Obama and at the Nobel Peace Prize concert in Oslo the next day.

Lang Lang has made numerous TV appearances, including on such shows as The Today Show, The Tonight Show with Jay Leno, Good Morning America, CBS Early Show and 60 Minutes. Lang Lang has been featured on various news and lifestyle magazines, including diverse publications such as The New Yorker, Esquire, Vogue (Germany), The Times (London), Financial Times, GQ, Die Welt, Reader's Digest and People. Lang Lang holds the title of the first Ambassador of the YouTube Symphony Orchestra.

In 2009, he performed at Carnegie Hall accompanied by Marc Yu the 11 year-old pianist and musical child prodigy from Pasadena, California who made his Carnegie Hall debut at the event.

In 2010, he will be featured at the Carnegie Hall's China Festival.

Lang Lang has stated his mission is to share classical music around the world, with an emphasis on training children and young musicians through education. The Financial Times noted that Lang Lang is "evangelical in his efforts to spread the popularity of classical music." In October 2008 he launched the Lang Lang International Music Foundation in New York with the support of the Grammy’s and UNICEF. The Lang Lang International Music Foundation was created to enrich the lives of children through a deeper understanding and enjoyment of classical music and to inspire and financially support the next generation of musicians. In May 2009, Lang Lang and his three chosen scholars from the foundation — Charlie Liu, Anna Larsen, and Derek Wang, aged between 8 and 10 years old — performed together on The Oprah Winfrey Show on "Oprah's Search for the World's Smartest and Most Talented Kids."

Lang Lang's biography, Journey of a Thousand Miles, published by Random House in eight languages, was released in the summer of 2008. Delacorte Press also released a version of his autobiography specifically for younger readers, entitled Playing with Flying Keys.

Lang Lang has received numerous awards and has been seen by millions of television viewers throughout the world. Lang Lang appeared in a Time 100 — Time magazine's annual list of the 100 Most Influential People in the World. In 2008, the Recording Academy named him their Cultural Ambassador to China. Most recently, Lang Lang has been chosen as an official worldwide ambassador to the 2010 Shanghai Expo. Lang Lang was recognized for his efforts by the United Nations' Children's Fund (UNICEF) who appointed him an international Goodwill Ambassador in 2004.