3. Maj (official name: Treći Maj Brodogradilište d.d.; lit. 'Third May Shipyard') is a Croatian shipyard, located in Rijeka. It builds mainly oil tankers, bulk cargo ships, and container ships. It also sometimes builds smaller passenger ferries or yachts. It employs approximately 2,850 workers, and is the largest shipyard in Croatia.
The first docks were erected in 1892 as an affiliate to the German Howaldtswerke from Kiel. After their rent expired in 1902, it had low activity until 1905 when three businessmen from Budapest resumed the operation, now under the name Danubius, renamed in 1911 to Ganz & co. Danubius.
