The Lotus Sūtra (Sanskrit: Saddharma Puṇḍarīka Sūtram, lit. 'Sūtra on the White Lotus of the True Dharma'; traditional Chinese: 法華經; simplified Chinese: 法华经; pinyin: Fǎhuá jīng; lit. 'Dharma Flower Sutra') is one of the most influential and venerated Buddhist Mahāyāna sūtras. It is the main scripture on which the Tiantai and its derivative schools--the Japanese Tendai and Nichiren, Korean Cheontae, and Vietnamese Thiên Thai schools of Buddhism--were established. It is also influential for other East Asian Buddhist schools, such as Zen. According to the British Buddhologist Paul Williams, "For many Buddhists in East Asia since early times, the Lotus Sūtra contains the final teaching of Shakyamuni Buddha—complete and sufficient for salvation." The American Buddhologist Donald S. Lopez Jr. writes that the Lotus Sūtra "is arguably the most famous of all Buddhist texts," presenting "a radical re-vision of both the Buddhist path and of the person of the Buddha."

Two central teachings of the Lotus Sūtra have been very influential for Mahāyāna Buddhism. The first is the doctrine of the One Vehicle, which says that all Buddhist paths and practices lead to Buddhahood and so they are all actually "skillful means" of reaching Buddhahood. The second is the idea that the lifespan of the Buddha is immeasurable, and that therefore, he did not really pass on into final Nirvana (he only appeared to do so as upāya), but is still active teaching the Dharma.

The earliest known Sanskrit title for the sūtra is the Saddharma Puṇḍarīka Sūtra, which can be translated as "the Scripture of the Lotus Blossom of the Fine Dharma" or "The Discourse on the White Lotus of the True Doctrine." In English, the shortened form Lotus Sūtra is more common.

Translations of this title into Asian languages include the following:

The Japanese Buddhist priest Nichiren (1222–1282) regarded the title as the summary of the Lotus Sūtra's teachings. The chanting of the title is the basic religious practice he advocated during his lifetime.

The Lotus Sūtra is known for its extensive instruction on skillful means (Sanskrit: upāyakauśalya or upāya, Ch.: fangbian, Jp.: hōben), which refers to how Buddhas teach in many ways adapted to the needs of their disciples. This concept of Buddhist pedagogical strategies is often explained through parables or allegories. In the Lotus Sūtra, the many 'skillful' or 'expedient' practices and teachings taught by the Buddha (including the "three vehicles" to awakening) are revealed to all be part of the "One Vehicle" (Skt.: ekayāna, Ch.:一乘; yīchéng), the supreme and all encompassing path that leads to Buddhahood. Moreover, this single vehicle is none other than the myriad skillful means which are its expressions and modes. As the Buddha says in the sutra, "seek as you will in all ten directions, there is no other vehicle, apart from the upāyas of the buddhas."

The One Vehicle is associated with the Mahāyāna ("Great Vehicle"), which is a path that rejects the cutting off of rebirth (the individual nirvana or "extinction" of the Buddhist saint) and seeks to heroically remain in the world of suffering to help others attain awakening, all while working towards complete Buddhahood. In the Lotus Sūtra, the One Vehicle encompasses many different and seemingly contradictory teachings because the Buddha's great compassion and wish to save all beings (bodhicitta) led him to adapt the teaching to suit many different kinds of people and contexts. As the Buddha states in the Lotus Sūtra: "Ever since I became a buddha, I have used a variety of causal explanations and a variety of parables to teach and preach, and countless skillful means to lead living beings."

The Lotus Sūtra declares also all other teachings are subservient to, propagated by and in the service of the ultimate truth of the "One Buddha–Vehicle", a goal that is available to all. This can and has been interpreted by some figures in an exclusive and hierarchical sense, as meaning that all other Buddhist teachings are to be dispensed with. However, Reeves and other interpreters understand the one vehicle in a more pluralist and inclusive sense which embraces and reconciles all Buddhist teachings and practices. Some have even applied this universalism to non-Buddhist teachings.