This particular category in the competition, which is sponsored by ScottishPower, attracted entries from Nevis Range in Fort William, Glasgow-based landscape architects City Design, salmon producer Scottish Sea Farms in Oban and the Kindrogan Field Centre in Perthshire.
The business awards are intended to recognise the impact of businesses on the economy, while the environmental award rewards commitment to minimising an organisation's impact on the environment.
Christina Potter, Elmwood's principal, said that the college is unique among educational establishments in its approach to environmental management.
It was the first college in the world to be accredited to a documented environmental management system. It converted land previously used for farming into an 18-hole golf course, which is regarded as a model of good environmental practice. And last year, the college was given the Wildlife Trust's biodiversity benchmark award.
Ms Potter said: "It is nice to know that the contribution which Scotland's colleges make to the economy is now being recognised and we, at Elmwood, are very, very proud of this achievement."