Quick answer
The Australian Red Ensign is Australia’s official merchant flag for Australian registered merchant ships at sea. It has a red field, the Union Jack in the upper hoist corner, a white Commonwealth Star below it and the white Southern Cross in the fly. See the government’s Red Ensign fact sheet.
| Feature | Specification and evidence |
|---|---|
| Overall proportions | 1:2 hoist:fly. PM&C describes the Red Ensign as sharing the national flag’s design except for its red background; its national-flag construction diagram specifies height X and length 2X. |
| Field and canton | Red field; Union Jack in the upper quarter next to the staff. |
| Commonwealth Star | White, seven-pointed star below the canton. |
| Southern Cross | Five white stars in the fly: four seven-pointed stars and the smaller five-pointed Epsilon Crucis. |
| Colour precision | Red, white and blue identify the design. No independently verified Red Ensign textile colour specification or exact digital colour values are supplied here. |
Construction and evidence limits
Use the government construction diagram as the dimensional reference, rather than measuring a reproduced image. It gives the Commonwealth Star an outer diameter of 3/10 of flag height; the four larger Southern Cross stars, 1/7; and Epsilon Crucis, 1/12. Each star’s inner diameter is 4/9 of its outer diameter. Applying this geometry to the Red Ensign follows PM&C’s statement that its design matches the national flag except for the background. See Australian Flags, page 4.
These are official design references, not evidence of a particular manufacturer’s fabric, stitching or tolerances. Screen colours are approximations, not certified textile matches.
History and current status
The 1901 competition requested designs for both an official and naval flag and a merchant flag. It produced blue and red ensigns. The Red Ensign was historically used both ashore and afloat, including during both world wars.
PM&C describes confusion over the two ensigns during the first half of the twentieth century, clarified by the Flags Act 1953: the blue ensign became the Australian National Flag, while the Red Ensign retained its merchant role. The competition date identifies the design’s origins, not proof that every detail of the present construction was fixed in 1901. See PM&C’s Australian flags history.
Frequently Asked Questions
Can the Australian Red Ensign be flown on land?
PM&C allows ceremonial land use, including Merchant Navy Day on 3 September. When displayed with the Australian National Flag, the national flag occupies the position of honour. See the official fact sheet.
How does it differ from the Australian National Flag?
The principal difference is the red background instead of blue; PM&C describes the remaining design as identical. Compare the Flag of Australia.