Home-grown firms are well represented, with four listed in the top six
Bord Bia has been named the most reputable organisation in Ireland.
The annual Ireland RepTrak 2016 study also ranks Eason & Son, An Post, Google and Lidl in the top five.
This is the seventh year of the study, compiled by The Reputations Agency.
It ranks the 100 largest and most visible organisations in Ireland, based on 5,093 responses gathered from the general public.
This year's report shows that organisations operating in food-related sectors were among those with the top reputations, with eight ranked in the top 20: Bord Bia (1st), Lidl (5th), Aldi (7th), SuperValu (11th), Kellogg's (14th), Glanbia (15th), Cadbury (16th) and Kerry Group (20th).
Indigenous Irish organisations were also well represented at the top, with four listed in the top six positions: Bord Bia (1st), Eason & Son (2nd), An Post (3rd), and The Irish League of Credit Unions (6th).
The reputation of the leading sporting bodies saw the IRFU achieving the highest ranking in that sector, at 23rd place overall. The GAA was ranked 49th, while FAI was placed in 95th position.
The independent study ranked each company on an average measure of four indicators: trust, esteem, admiration and good feeling.
It also studied how organisations were rated across the more rational dimensions of leadership, products and services, innovation, governance, workplace, performance and citizenship.
The report says companies investing in building their reputation are "winning competitive advantage".
"Ryanair's continued focus on customer experience with its 'Always Getting Better' programme, now in its third year, has seen it rise from 99th place in 2013 to 63rd position in 2016. During that period its share price has almost tripled", it says.
One of the key findings from report was that the reputation of firms among the general public fell slightly in 2016, having flat-lined in 2015.