Christian Augustus Siebe (known by his middle name; 1788 – 15 April 1872) was a British engineer chiefly known for his contributions to diving equipment.
Contribution to diving
thumb|upright|Siebe's design, as refined by 1873.
In the 1830s the Deane brothers asked Siebe to make a variation of their smoke helmet design for underwater use.
Other inventions
thumb|Vulcan medal from the [[Royal Society of Arts]]
Besides his contributions to diving he also invented:
- a rotating water pump patented in 1828,
- A paper making machine,
- a Dial weighing scale,
- an ice-making machine (with James Harrison).
In 1823, Siebe won the Vulcan medal from the Royal Society of Arts for an improved screw threading tool.
Siebe won many medals at the Great Exhibition in 1851 and the Paris Exhibition in 1855.
He died 15 April 1872 of chronic bronchitis, at his London home.