Castle Menzies, its Walled Garden and the Old Kirk of Weem are held and maintained by The Castle Menzies SCIO, a registered charity (a Scottish Charitable Incorporated Organisation) under charity number SC051439, regulated by OSCR.

Following the purchase of Castle Menzies as a ruin in 1957 and the subsequent extensive restoration works by the Menzies Clan Society, which maintains a very close association with the Castle, Castle Menzies was placed into a charitable body in order to continue to enjoy charitable status following a change in charities legislation in 1992.  In 1993 The Menzies Charitable Trust was therefore formed for this purpose, which then converted into The Castle Menzies SCIO (TCMS) in 2023.

The Menzies Clan Society maintains close links with TCMS but the Society no longer owns or maintains the Castle: such functions are solely carried out by TCMS.

Under its constitution, TCMS's trustees include the President and Treasurer of the Menzies Clan Society and a representative of the current Chief of the Clan Menzies.

TCMS runs the Castle, Gardens and the Old Kirk of Weem for the benefit of the nation as a national monument, museum, clan centre and visitor attraction.

Current trustees:

• Pauline Wyllie, Chair
• Neil Menzies, Secretary
• Luke Menzies, Treasurer
• George Menzies
• John McKenna
• Sandy Lyell