Birt Acres (23 July 1854 – 27 December 1918) was an American and British photographer and film pioneer.

He contributed much to the introduction and development of cinematography in all its aspects, from the construction of cameras, projectors, film viewers, coating and slitting machines and the manufacture of highly sensitized 35 mm raw film stock, to mobile newsreel reporting and the public projections of moving pictures.

[citation needed] With his partner Robert W. Paul, he was the first person to build and run a working 35 mm camera in Britain.

On 10 January 1896, he gave a display of moving pictures to the Lyonsdown Photographic Society at the Lytton Road Assembly Rooms in New Barnet.

On 14 January 1896, he demonstrated his Kineopticon system to members and wives of the Society, at the Queen's Hall in London.