New regulations have come into force prohibiting the manufacture and sale of the items, as part of measures to reduce plastic waste.
Environmental campaigners at the Marine Conservative Society, who have cleared more than 150,000 plastic cotton bud sticks from Scotland's beaches over the last 25 years, hailed the move as a "fantastic win" for the sea and wildlife.
The ban comes in as regulations, which were laid in the Scottish Parliament in September, take effect.
A ban on the sale and manufacture of plastic micro beads is already in place, having been introduced in June 2018.
Scottish Environment Secretary Roseanna Cunningham said: "I am proud that the Scottish Government has become the first UK administration to ban plastic-stemmed cotton buds.
"Single-use plastic products are not only wasteful but generate unnecessary litter that blights our beautiful beaches and green spaces while threatening our wildlife on land and at sea.
"This ban builds on work already under way to address Scotland's throw-away culture, and we will continue to take action on other problematic items in the coming years as part of our efforts to reduce harmful plastics and single-use items, protect our environment and develop a thriving circular economy."
Ms Cunningham added: "We are facing a global climate emergency and must all work together to reduce, reuse and recycle to ensure a sustainable future for the current and next generation."
Catherine Gemmel, of the Marine Conservative Society, said its volunteers had "picked up over 150,000 plastic cotton bud sticks from Scottish beaches over the last 25 years so this ban coming into force is a fantastic win for our seas and wildlife".
She added: "We look forward to more ambitious action from the Scottish Government and to working with them on further actions needed to stop the plastic tide."
WWF Scotland director Lang Banks also described the ban as "great news for wildlife".
He stated: "Cotton buds are some of the most pervasive forms of marine pollution so a ban is very welcome and a step and one that we hope other countries will follow.
"We know plastic is suffocating our seas and devastating our wildlife with millions of birds, fish and mammals dying each year because of the plastic in our oceans.
"Plastics are also finding their way into the food we eat and the water we drink so saving our oceans will require further ambitious action from governments, industry and consumers."