The Scout Association said its membership has shot up from 450,455 to 550,457 members in the last decade, and in this time female membership has grown from 69,996 to 128,042.
The number of adults volunteering has increased by 14,596 in 10 years to a total of 104,28, but more than 40,000 young people want to join and are unable to because more adult volunteers are required to help, the Association said.
The figures are based on findings from the Scout Association's latest census, which is carried out annually to identify trends and development areas in the movement. The Forth region has seen the highest growth in the past year. The association is launching a plan to recruit a further 58,000 young people by 2018.
Over the past 18 months, the movement said it has focused on delivering its youth work in more deprived parts of the UK, using funding supplied by the UK Government via the Youth United Foundation. It has enabled the recruitment of 1,553 more young members and 315 adult volunteers.
Wayne Bulpitt, UK chief commissioner, said: "We have a clear plan to make the movement more diverse, more community-focused and more youth-led in the next four years."
Chief Scout Bear Grylls said being a Scout "empowers" people, and he said he is "excited" to see membership increasing.
He said: "I am excited to see Scout numbers continue to rise across the UK and the big reasons for this are that more and more young people are realising that Scouting can give them so much.
"Scouting brings them all together, empowers them and allows them to make a positive impact," he added.