The oddly-named Alldays & Onions was an English automobile that was manufactured from 1898 to 1918. The car was a product of Alldays & Onions Pneumatic Engineering Co. of Birmingham, a company founded in 1889 by the merger of the long established Onions (dating from 1650) and Alldays (dating from 1720) engineering companies. Like many such companies they turned to bicycle manufacture and sold a range under the Alldays name. They also started making motorcycles in 1903 under the Alldays-Matchless name, this had no connection with the London based Matchless company, and in 1915 presumably following representations from them, the name was changed to Allon.
Manufacture of these continued until 1927. In 1898 they made their first car, the Traveller but series production did not start until 1903/4 with the 7hp model. Larger commercial vehicles of up to 5 tons were also made in the years preceding the first World War and saw service during the conflict.
Alldays & Onions merged with Enfield, a company they had owned since 1907 and produced cars called Enfield-Allday until 1925.