New Era quoted the Namibia Statistics Agency (NSA) as saying that the increase in production was mainly due to improved marine operations.
The agency said the southern African country produced 126 917 carats in November from the previous month's 116 001 carats.
Namibia produced 124 646 carats in the comparative period in 2019.
The positive growth recorded in the country's diamond sector was not replicated in other mining sectors as the mining composite index fell 16.2% in November 2020 compared to the previous month and 7.3% for November 2019.
The Bank of Namibia said last month that it was expecting the country's diamond mining sector's 2020 output to decline by 14.7%.
The 14.7% contraction estimated for 2020, however, represented an improvement from a deeper contraction of 24.7% during August 2020.
Namibia produced just above 2 million carats in 2019, according to the Kimberley Process.
Mathew Nyaungwa, Editor in Chief of the African Bureau, Rough&Polished