Nigerian President Goodluck Jonathan originally commissioned the brewery in August 2012.
SABMiller made an initial investment of over US$100m in the Onitsha brewery, making it the largest single investment in Anambra State for almost 20 years.
"Due to our growth and in particular the success of Hero Lager, a further US$110 m will be invested in the brewery to triple its current annual capacity from 700 000 to 2.1 million hectolitres," said Simon Harvey, SABMiller Nigeria's managing director.
Currently, the business directly employs 300 local people and the investment will lead to the creation of a further 400 direct jobs.
“We have made significant investments over the past five years in Nigeria and this announcement demonstrates our ongoing commitment in the country,” said Harvey.
The capacity expansion work has already commenced and is due for completion in the first quarter of 2015.
The brewery will continue to produce brands including Hero Lager, Castle Milk Stout and non-alcoholic malt beverages Grand Malt and Beta Malt.