Alumex PLC is an aluminium extrusions manufacturing company in Sri Lanka.

Sri Lankan conglomerate Hayleys acquired Alumex in 2010 and was listed on the Colombo Stock Exchange after an initial public offering in 2014.

Alumex is the leading aluminium manufacturer in Sri Lanka, with a market share of 46%.

The company was incorporated in 1986 as Alumex (Pvt) Ltd, a South Korean-Sri Lankan joint venture.

The Sri Lankan partners of the joint venture took control of the South Korean stake in 2006.

LMD 100, analogous to Fortune 500, lists publicly traded companies in Sri Lanka by revenue.