Gregory "Greg" John Noonan was an American brewing expert who wrote several published books on brewing. His writing credits include Brewing Lager Beer: The Most Comprehensive Book for Home - And Microbrewers (1986) which he updated in 1996 and changed the title to New Brewing Lager Beer: The Most Comprehensive Book for Home - And Microbrewers. He also wrote Scotch Ale (1993) for the Classic Beer Styles Series from Brewers Publications. He co-authored Seven Barrel Brewery Brewers Handbook (1997) with Mikel Redman and Scott Russell.