Exhibit 21
SUBSIDIARIES OF SOLUNA HOLDINGS, INC.
| Subsidiary Name | Jurisdiction of Incorporation or Organization |
| Soluna Computing, Inc. | Nevada |
| Soluna Digital, Inc. | New York |
SUBSIDIARIES OF SOLUNA DIGITAL, INC.
| Subsidiary Name | Jurisdiction of Incorporation or Organization |
| Soluna MC, LLC | Nevada |
| Soluna SW, LLC | Nevada |
Soluna Callisto Holdings, Inc. |
Delaware |
| Soluna DV Devco, LLC | Delaware |
| Soluna DV ComputeCo, LLC | Nevada |
| Soluna DV Services, LLC | Delaware |
SUBSIDIARIES OF SOLUNA MC, LLC
| Subsidiary Name | Jurisdiction of Incorporation or Organization |
| Soluna MC Borrowings, LLC 2021-1 | Delaware |
SUBSIDIARIES OF SOLUNA SW, LLC
| Subsidiary Name | Jurisdiction of Incorporation or Organization |
| Soluna SW Borrowings, LLC 2022-1 | Delaware |
SUBSIDIARIES OF DV DEVCO, LLC
| Subsidiary Name | Jurisdiction of Incorporation or Organization |
| Soluna DVSL ComputeCo, LLC | Delaware |