Michael Reader killed Marion Price with a shotgun as she sat in her car outside her home after he tracked her movements for months.
A court heard the "money-obsessed" 70-year-old carried out the "calculated murder" after he "bitterly resented" being told to pay his ex-partner £10,000 just a few days earlier.
He gunned down 63-year-old Marion as he drove by her Vauxhall Corsa on his motorbike.
He shot her once through the window before she'd had chance to take off her seatbelt.
Marion's family later discovered the gran-of-three's body slumped in the front seat of the car outside her home on December 15, last year.
Emergency services rushed to the scene, in the quaint village of Earls Barton, Northants., but the school finance worker was pronounced dead at the scene.
Jurors were told how Reader lay in wait and killed Marion because he did not want to part with his money following a bitter legal row over their finances.
Reader was found guilty of murder alongside best friend and "trusted lieutenant" Stephen Welch, 61.
On Monday, at Northampton Crown Court, Reader was jailed for life to serve a minimum of 31 years - meaning he is likely to die behind bars.
Welch, who was also found guilty of murder, was also jailed for life with a minimum of 27 years.
Sentencing, Judge Adrienne Lucking QC told Reader: "You shot Marion Price through the window of her car out of jealousy and as an act of cold-blooded revenge.
"Before her marriage to you, Marion Price was a happy person. But you were controlling and obsessed with money. In private, you ridiculed and undermined her.
"You were incensed. You were bitter and resentful and you became jealous of her social life and obsessed with her movements.
"She had no idea what was about to happen. "But I am certain that she saw her killer at the last moment because as she was shot, she raised her hand to protect herself.
Addressing Welch, who the judge added: "You were a willing assistant who joined in a plan to murder Marion Price to help your friend.
"No sentencing I pass today can ease the pain for her (Marion's) family."
The eight-week trial heard how Reader was a manipulative bully who couldn't stand Marion taking back control of her life after she plucked up the courage to leave him.
Over the course of several months Reader, assisted by Welch, stalked her by tracking her movements before murdering her in December last year.
After the killing, Welch picked his friend of more than 30 years up and dumped items in the River Nene in Northampton, before flying to Spain.
Jurors heard how loving grandmother Marion and Reader met online in 2012 and embarked on a whirlwind romance, marrying just months later.
But weeks later, the mum-of-two told a colleague she feared she'd made a big mistake and Reader was "not who she thought he was".
Police said Reader had abused and manipulated Marion, belittling her, making derogatory comments about her appearance, and turning the "fun mum" her children knew into someone who was "constantly on edge."
She began to lack in confidence, her work suffered, and gradually, she became depressed before Marion left him in 2016.
He denied having seen her despite phone data placing him at the scene, witnesses saying he had previously threatened to kill her and a jacket with gunshot residue being found at his house.
Marion's family stood up in court to give emotional statements about how the killing of the woman adored by so many people had left a huge hole in their lives.
Eight of those on the jury returned to court today with some in tears as they heard the statements.
Both Reader and Welch showed no emotion as they listened to how their actions had impacted on Marion's family.
In a statement read by prosecutor Mary Loram QC, Marion's elder sister Helen said "Since Marion was murdered I have lost not only a much-loved sister but a best friend too."
Marion's son Gary Price, said he hoped by reading about Marion's story that others would be able to spot that they were in an abusive relationship.
He added: "Life for us will never be the same...I cannot believe that I will never get to hug my mum again."
Marion's son-in-law Scott Brown, who took to the witness box to read a statement from him and Toni Brown, his wife and Marion's daughter, said the family had had their "hearts shattered into pieces".
But he added: "Mike has not won."
Detective Chief Inspector Joe Banfield, of Northamptonshire Police, said after the case: "This has been a very complex and emotive case to investigate.
"I am pleased to see Reader and Welch both receive substantial sentences for the cold-blooded crime they committed.
"Marion Price was so much more than Michael Reader's 'victim'. She was a mother, a sister, a grandmother, a daughter and a friend.
"She was so loved by everyone who knew her and universally described as a lovely woman with a great sense of humour.
"Her memory will live on and my thoughts will remain with her family long into the future."