Zero Waste Scotland said meat and fish worth £190 million is being discarded each year. Beef, lamb, pork and poultry alone account for 22,000 tonnes of waste worth £140 million.
The organisation says that reducing avoidable food waste could save every household up to £460 a year.
It has teamed up with Ayrshire butchers We Hae Meat to issue tips and recipes to help people make the most of their meat.
Ylva Haglund, food waste campaign manager at Zero Waste Scotland, said: "Our research has shown that despite our love of beef in Scotland, we still throw away millions of pounds worth every year, with an equivalent weight to 26 million burgers, or the weight of 13 million steaks, in Scotland."
The organisation says its research shows that much waste could be avoided by taking small steps at home, such as planning meals in advance, storing food better, understanding date labels, serving the right portions and cooking with leftovers.
Scottish households throw away over £5 million of food each year because it was not used in time, campaigners said, while confusion over dates labels, caution over meat safety and worries over freezing and reheating can lead to good meat being thrown away when it is still fine to eat.
Jim McLaren, chairman of Quality Meat Scotland (QMS), said: "QMS has been promoting the use of leftover beef, lamb and pork for more than a decade and the 300 members of our Scotch Butchers Club all use our leftover campaign information and recipes to encourage their customers to make the most of meat."
The Scottish Government recently announced a target to reduce food waste by 33% by 2025.
Zero Waste Scotland is funded by the Holyrood administration to support the delivery of its zero waste plan.