Youth membership has also fallen in the past year
The Scouts want to recruit more adult volunteers after losing 15,000 during the coronavirus pandemic.
The movement is launching the #GoodForYou campaign which aims to recruit at least 5,000 volunteers after adult volunteer numbers fell from 155,907 in 2020 to 140,810 in 2021.
This drop in numbers follows a sustained period of growth, where total membership rose by nearly 200,000 between 2006 and 2020.
Youth membership has also fallen by 24.5% over the past year, from 480,083 to 362,752.
The Scouts say the numbers are an indicator of how the pressures and disruptions to life mean not all youth members have been able to continue in the movement, adding that this is especially the case in communities disproportionately impacted by the pandemic.
The Scouts will be running a series of locally-focused recruitment campaigns encouraging new volunteers to join, as well as inviting young people and adults who drifted away during the pandemic to re-join and create new Scout groups in areas of greatest need.
Jobs will be created for 66 young adults through the Government’s Kickstarter programme, and new team members will work as development officers to support Scout groups to welcome new members.