Allium obliquum, common name lop-sided onion or twisted-leaf onion, is a Eurasian species of wild onion with a range extending from Romania to Mongolia. It is also widely cultivated elsewhere as an ornamental.

Allium obliquum produces an egg-shaped bulb up to 3 cm long. Scape is up to 100 cm tall, round in cross-section. Leaves are flat, shorter than the scape, up to 20 mm across. Umbels are spherical, with many yellow flowers crowded together.