Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2021	Nov. 10, 2021
Document Type	10-Q
Document Period End Date	Sep. 30, 2021
Document Quarterly Report	true
Document Transition Report	false
Entity File Number	000-50626
Entity Registrant Name	Cyclacel Pharmaceuticals, Inc.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	91-1707622
Entity Address, Address Line One	200 Connell Drive
Entity Address, Address Line Two	Suite 1500
Entity Address, City or Town	Berkeley Heights
Entity Address, State or Province	NJ
Entity Address, Postal Zip Code	07922
City Area Code	908
Local Phone Number	517-7330
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Shell Company	false
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q3
Entity Central Index Key	0001130166
Amendment Flag	false
Entity Common Stock, Shares Outstanding		9,975,135
Common Stock [Member]
Title of 12(b) Security	Common Stock, par value $0.001 per share
Trading Symbol	CYCC
Security Exchange Name	NASDAQ
Preferred Stock [Member]
Title of 12(b) Security	Preferred Stock, $0.001 par value
Trading Symbol	CYCCP
Security Exchange Name	NASDAQ