Riley was born in Norwood, London in 1931. Her father, John Fisher Riley, originally from Yorkshire, had been an Army officer. He was a printer by trade and owned his own business. In 1938 he relocated the printing business, together with his family, to Lincolnshire.

Between 1956 and 1958, she nursed her father, who had been involved in a serious car crash. She suffered a breakdown due to the deterioration of her father’s health. After this she worked in a glassware shop. She eventually joined the J. Walter Thompson advertising agency, as an illustrator, where she worked part-time until 1962. The Whitechapel Gallery exhibition of Jackson Pollock in the winter of 1958 had an impact on her.

Riley’s mature style, developed during the 1960s, was influenced by a number of sources, including the French Post-Impressionist artist Georges Seurat. In 2015-6, the Courtauld Gallery, in its exhibition Bridget Riley: Learning from Seurat, made the case for how Seurat’s pointillism influenced her towards abstract painting. As a young artist in 1959, Riley saw The Bridge at Courbevoie, owned by the Courtauld, and decided to paint a copy. The resulting work has hung in Riley’s studio ever since, barring its loan to the gallery for the exhibition, demonstrating in the opinion of the art critic Jonathan Jones “how crucial” Seurat was to her approach to art. Riley described her copy of Seurat’s painting as a “tool”, interpreted by Jones as meaning that she, like Seurat, practised art “as an optical science”; in his view, Riley “really did forge her optical style by studying Seurat”, making the exhibition a real meeting of old and new. Jones comments that Riley investigated Seurat’s pointillism by painting from a book illustration of Seurat’s Bridge at an expanded scale to work out how his technique made use of complementary colours, and went on to create pointillist landscapes of her own, such as Pink Landscape (1960), painted soon after her Seurat study and portraying the “sun-filled hills of Tuscany” (and shown in the exhibition poster) which Jones writes could readily be taken for a post-impressionist original. In his view, Riley shares Seurat’s “joy for life”, a simple but radical delight in colour and seeing.

Riley is a Patron of Paintings in Hospitals, a charity established in 1959 to provide art for health and social care in England, Wales and Northern Ireland.

In 1961, she and her partner Peter Sedgley visited the Vaucluse plateau in the South of France, and acquired a derelict farm which they eventually transformed into a studio. Back in London, in the spring of 1962, Victor Musgrave of Gallery One held her first solo exhibition.

In 1963, Riley was awarded the AICA Critics Prize as well as the John Moores, Liverpool Open Section Prize. A year later, she received a Peter Stuyvesant Foundation Travel bursary. Riley has been given honorary doctorates by Oxford (1993) and Cambridge (1995). In 1968, she received an International Painting Prize at the Venice Biennale. In 2003, she was awarded the Praemium Imperiale, and, in 1998, she became one of only 65 Companions of Honour in Britain. As a board member of the National Gallery in the 1980s, she blocked Margaret Thatcher’s plan to give an adjoining piece of property to developers and thus helped ensure the eventual construction of the museum’s Sainsbury Wing. Riley has also received the Kaiserring of the city of Goslar in 2009 and the 12th Rubens Prize of Siegen in 2012. Also in 2012, she became the first woman to receive the Sikkens Prize [nl], the Dutch art prize recognising the use of colour.

In 1965, Riley exhibited in the Museum of Modern Art in New York City show, The Responsive Eye (created by curator William C. Seitz); the exhibition which first drew worldwide attention to her work and the Op Art movement. Her painting Current, 1964, was reproduced on the cover of the show’s catalogue. Riley became increasingly disillusioned, however, with the exploitation of her art for commercial purposes, discovering that in the USA there was no copyright protection for artists. The first US copyright legislation was eventually passed, following an independent initiative by New York artists, in 1967.

Riley began investigating colour in 1967, the year in which she produced her first stripe painting. Following a major retrospective in the early 1970s, Riley began travelling extensively. After a trip to Egypt in the early 1980s, where she was inspired by colourful hieroglyphic decoration, Riley began to explore colour and contrast. In some works, lines of colour are used to create a shimmering effect, while in others the canvas is filled with tessellating patterns. Typical of these later colourful works is Shadow Play.

In 1968 Riley, with Sedgley and the journalist Peter Townsend, created the artists’ organisation SPACE (Space Provision Artistic Cultural and Educational), with the goal of providing artists large and affordable studio space.

She participated in documentas IV (1968) and VI (1977). In 1968, Riley represented Great Britain in the Venice Biennale, where she was the first British contemporary painter, and the first woman, to be awarded the International Prize for painting. Her disciplined work lost ground to the assertive gestures of the Neo-Expressionists in the 1980s, but a 1999 show at the Serpentine Gallery of her early paintings triggered a resurgence of interest in her optical experiments. “Bridget Riley: Reconnaissance”, an exhibition of paintings from the 1960s and 1970s, was presented at Dia:Chelsea in 2000. In 2001, she participated in Site Santa Fe, and in 2003 the Tate Britain organised a major Riley retrospective. In 2005, her work was featured at Gallery Oldham. Between November 2010 and May 2011, her exhibition “Paintings and Related Work” was presented at the National Gallery, London.

Following a visit to Egypt in 1980–81, Riley created colours in what she called her ‘Egyptian palette’ and produced works such as the Ka and Ra series, which capture the spirit of the country, ancient and modern, and reflect the colours of the Egyptian landscape. Invoking the sensorial memory of her travels, the paintings produced between 1980 and 1985 exhibit Riley’s free reconstruction of the restricted chromatic palette discovered abroad. In 1983, for the first time in fifteen years, Riley returned to Venice to once again study the paintings that form the basis of European colourism. Towards the end of the 1980s, Riley’s work underwent a dramatic change with the reintroduction of the diagonal in the form of a sequence of parallelograms used to disrupt and animate the vertical stripes that had characterized her previous paintings. In Delos (1983), for example, blue, turquoise, and emerald hues alternate with rich yellows, reds and white.

Between 1987 and 2014, she created three murals across the eighth, ninth and tenth floors of the Queen Elizabeth Queen Mother Wing, St Mary’s Hospital, London.

Riley has written on artists from Nicolas Poussin to Bruce Nauman. She co-curated Piet Mondrian: From Nature to Abstraction (with Sean Rainbird) at the Tate Gallery in 1996. Alongside art historian Robert Kudielka, Riley also served as curator of the 2002 exhibition “Paul Klee: The Nature of Creation”, an exhibition at the Hayward Gallery in London in 2002. In 2010, she curated an artists choice show at the National Gallery in London, choosing large figure paintings by Titian, Veronese, El Greco, Rubens, Poussin, and Paul Cézanne.

In 2006, her Untitled (Diagonal Curve) (1966), a black-and-white canvas of dizzying curves, was bought by Jeffrey Deitch at Sotheby’s for $2.1 million, nearly three times its $730,000 high estimate and also a record for the artist. In February 2008, the artist’s dotted canvas Static 2 (1966) brought £1,476,500 ($2.9 million), far exceeding its £900,000 ($1.8 million) high estimate, at Christie’s in London. Chant 2 (1967), part of the trio shown in the Venice Biennale, went to a private American collector for £2,561,250 ($5.1 million), in July 2008, at Sotheby’s.

Artists Ross Bleckner and Philip Taaffe made paintings paying homage to the work of Riley in the 80s. In 2013, Riley claimed that a wall-sized, black-and-white checkerboard work by Tobias Rehberger plagiarised her painting Movement in Squares and asked for it to be removed from display at the Berlin State Library’s reading room.

Riley has painted temporary murals for the Tate, the Musée d’Art Moderne de la Ville de Paris and the National Gallery. In 2014, the Imperial College Healthcare Charity Art Collection commissioned her to make a permanent 56-metre mural for St Mary’s Hospital, London; the work was installed on the 10th floor of the hospital’s Queen Elizabeth Queen Mother Wing, joining two others she had painted more than 20 years earlier. In 2017, she installed a striped mural that circumnavigated a U-shaped former army barracks at the Chinati Foundation in Marfa, Texas, that expanded on a work executed for the Royal Liverpool Hospital in 1983.

In November 2015, the exhibition Bridget Riley opened at David Zwirner in New York. The show features paintings and works on paper by the artist from 1981 to present; the fully illustrated catalogue features an essay by the art historian Richard Shiff and biographical notes compiled by Robert Kudielka.

Between 2017 and 2019 Riley’s wall painting for the Chinati Foundation, Marfa, Texas was the artist’s largest work to date and spanned six of the eight walls of the building. The mural referenced Royal Liverpool University Hospital’s wall painting Bolt of Colour (1983) and revisited the artist’s Egyptian palette.

In 2017, alongside Yoko Ono and Tracey Emin, Riley donated artworks to an auction to raise money for Modern Art Oxford.