Navis actuaria (plural: naves actuariae) was a type of transport ship used by the Roman navy.
The ship had sails and up to 30 oars (15 on each side). They were short, narrow at bow and stern. and wider midships. They had a flat hull, so that they could run aground without being damaged. Furthermore, the Navis actuaria could go ashore both forwards and backwards, since it was equipped with rudders fore and aft. The ship could run aground on a beach, unload, and depart without damage. The ship was therefore suitable for the transport of supplies and horses.
It is believed that a navis actuaria was 21 metres (69 feet) long and 6.5 metres (21 feet) wide. The ship's draft was low (about 0.80–0.90 metres (2 ft 7 in–2 ft 11 in). Most of the naves actuariae were not armed. However, ships that were used in 16 CE under general Germanicus, carried light weaponry.
The navis actuaria should not be confused with the navis lusoria, which was a small patrol boat used in Late Antiquity.