Widdecombe, who was a former Conservative party minister and later a member of Nigel Farage's populist Reform UK, was found on July 9 at her home in rural southwest England after sustaining what police described as serious injuries.
She stood down from parliament in 2010.
Joshua Kerry, from Rotherham in northern England, has been charged with her killing, the Crown Prosecution Service said.
He was first arrested on suspicion of murder on July 11, two days after the 78-year-old Reform UK spokeswoman was found dead at her home in Devon.
On July 13 he was additionally arrested on suspicion of the commission, preparation or instigation of acts of terrorism.
He will appear at London's Westminster Magistrates' Court on Tuesday.
"Police inquiries into the defendant's motives are ongoing, including a potential political or terrorist connection," police said.
Widdecombe was first elected as a Conservative MP in Kent in 1987, and went on to become an MEP for the Brexit Party and then a spokeswoman for Reform UK.
She also found fame outside politics after starring in TV shows Strictly Come Dancing and Celebrity Big Brother.
with AP and PA
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