v3.24.3
Cover Page - shares
9 Months Ended
Sep. 30, 2024
Nov. 11, 2024
Cover [Abstract]    
Document Type 10-Q  
Document Quarterly Report true  
Document Period End Date Sep. 30, 2024  
Document Transition Report false  
Entity File Number 001-41526  
Entity Registrant Name CASTELLUM, INC.  
Entity Incorporation, State or Country Code NV  
Entity Tax Identification Number 27-4079982  
Entity Address, Address Line One 1934 Old Gallows Road  
Entity Address, Address Line Two Suite 350  
Entity Address, City or Town Vienna  
Entity Address, State or Province VA  
Entity Address, Postal Zip Code 22182  
City Area Code 703  
Local Phone Number 752-6157  
Title of 12(b) Security Common Stock, par value $0.0001 per share  
Trading Symbol CTM  
Security Exchange Name NYSEAMER  
Entity Current Reporting Status Yes  
Entity Interactive Data Current Yes  
Entity Filer Category Non-accelerated Filer  
Entity Small Business true  
Entity Emerging Growth Company true  
Entity Ex Transition Period true  
Entity Shell Company false  
Entity Common Stock, Shares Outstanding   56,109,928
Entity Central Index Key 0001877939  
Current Fiscal Year End Date --12-31  
Document Fiscal Year Focus 2024  
Document Fiscal Period Focus Q3  
Amendment Flag false