The Great Britain Tourism Survey, compiled by national tourist boards, suggested a strong domestic market.
However, a separate Office for National Statistics (ONS) survey showed a 4% fall in the number of international visitors in the first three quarters.
This was despite an 18% rise in tourist numbers from North America.
Just over 12 million people visited Scotland between January and September.
Spending by visitors from Britain rose by 21% year-on-year to about ??2.3bn, while expenditure by overseas tourists fell by 6% to just over ??1.1bn.
Tourism Minister Fergus Ewing described the overall figures as "encouraging".
Mr Ewing said: "The staycation market is continuing to boost visitor numbers and average spend also rising.  We will continue to invest in this market and the recently launched Year of Creative Scotland will help generate even more opportunities to do so.
"An 18% increase in visitors from North America is extremely welcome and evidence that this market is continuing to pick up after a tough time.
"This is offset by an overall fall of 4% in the number of international visitors to Scotland but we have to remember that tough times in the eurozone will have an impact."
Mr Ewing added the Scottish government would work with tourism body VisitScotland to ensure the industry was "in the best possible shape" to make the most of opportunities in the next three years, including the Ryder Cup and the Commonwealth Games in 2014.
Scottish Labour tourism spokeswoman Rhoda Grant said: "These figures show a welcome increase in staycations, but a disappointing drop in overseas visitors - we need both to increase if Scottish tourism is to thrive.
"Big events, like the Glasgow 2014 Games, offer a once in a lifetime opportunity to showcase Scotland to the world. The SNP government must redouble its efforts to capitalise on events like this."
She added: "While there is a small increase in hotel stays, in areas where there is a high concentration of small businesses - such as B&B and self-catering accommodation - we are seeing a worrying drop in tourism.
"I urge VisitScotland to focus on doing all it can to support small businesses like these."
The number of visitors to Scotland rose by 8% in the first nine months of last year as staycations grew in popularity, according to new figures.