Anna-Rosalie Boch was born on 10 February 1848 at Saint-Vaast, in the Belgian Hainaut, into one of Europe's great industrial dynasties — the Boch family, makers of fine earthenware at Keramis in La Louvière and, through their Villeroy & Boch cousins, across the continent. Wealth gave her independence, and she used it, unusually for a woman of her time and class, to become a serious painter, a discerning collector and a generous patron rather than a hostess. She never married, living much of her life alongside her younger brother, the painter Eugène Boch, and devoting herself to art, travel and music; an accomplished pianist, organist and violinist, she counted her feeling for harmony as central to her painting.

She trained in Brussels under Isidore Verheyden and Théodore Baron, but the decisive encounter came through Les XX, the avant-garde circle founded in 1883 by her cousin, the critic Octave Maus. Boch joined in 1885 and remained its only female member — a remarkable position in a group that gathered James Ensor, Fernand Khnopff and Théo van Rysselberghe, and that brought Seurat, Van Gogh, Gauguin, Pissarro and Toulouse-Lautrec to exhibit in Brussels. It was there, before Seurat's Grande Jatte and under the guidance of Van Rysselberghe — who became her friend and painted her portrait — that she embraced Neo-Impressionism, adopting the divisionist method of small, separate touches of unmixed colour. In time her handling loosened into a freer, sunlit Impressionism, but the divisionist's faith in pure colour and vibrating light stayed with her to the end.

Boch painted the world she moved through. She worked in the open air along the Belgian coast at Ostend — the city of her friend Ensor — and on the North Sea; she travelled to Brittany in 1901 and 1912, to Provence and the Riviera at Menton and Sanary, and through the Low Countries, returning always to gardens, orchards, undergrowth and shoreline. Hers is an art of sensation and atmosphere rather than incident: luminous church interiors, meadows dissolving into flecks of colour, coastal cliffs under changing skies. She exhibited widely — with Les XX and its successor La Libre Esthétique, and at the salons, including the 1907 Salon des Beaux-Arts at Ostend, alongside Anna De Weert, Louise Danse and Marie-Antoinette Marcotte.
Her eye as a collector was as bold as her brush. She assembled one of the most important private holdings of modern painting of her generation — Gauguin, Seurat, Signac, Ensor, Bernard, Monet, Meunier — and championed the unknown. In 1890, at the Les XX exhibition, she bought Van Gogh's La Vigne rouge (The Red Vineyard) for 400 francs, long held to be the only painting he sold in his lifetime; she later added his Plaine de la Crau. The Van Gogh connection ran through the family: her brother Eugène, trained under Bonnat and Cormon and introduced to the painter by Dodge MacKnight, became Van Gogh's friend and the sitter for the celebrated portrait now in the Musée d'Orsay.

Anna Boch died in Brussels in 1936 and is buried in the Ixelles cemetery. By her will she directed that her collection be sold to fund pensions for her poorer artist friends; The Red Vineyard passed, through that sale, to the Russian collector Sergei Shchukin, and hangs today in the Pushkin Museum, Moscow. For decades her own painting was overshadowed by the artists she had supported, but recent scholarship and a catalogue raisonné (Dr Thérèse Thomas, 2005) have restored her standing. Major retrospectives at the Royal Museum of Mariemont (2000), the Mu.ZEE in Ostend (2023) and the Musée de Pont-Aven (2024), and her inclusion in the National Gallery's Radical Harmony (London, 2025), confirm her now as one of the outstanding Belgian Neo-Impressionists and a pivotal figure of the Brussels avant-garde. Her work is held by the Royal Museums of Fine Arts of Belgium, the Mu.ZEE, the Museum of Fine Arts in Ghent and the Musée d'Orsay.