Shanna Gardner, 36, entered her plea on Friday after she was indicted by a grand jury on first-degree murder, conspiracy to commit first-degree murder, solicitation to commit a capital felony, and child abuse charges in connection with the shooting death of Mr Bridegan on his way home from her house in Florida in 2022.
Mr Bridegan, 33, was shot and killed after visiting Ms Gardner to drop off their shared children. On his way home, he encountered an obstruction on a road nearby and exited his car to move it so he could pass. Once he was outside of his car he was shot and killed. A bullet narrowly missed one of his children from his second marriage who was strapped into a carseat.
Ms Gardner's current partner, Mario Fernandez Saldana, and one of his tenants were also implicated in the shooting. She was arrested in August in Washington state, where she moved following Mr Bridegan's murder. She was extradited to Duval County last month after losing a legal petition to stay in Washington.
She appeared in court for the first time on Friday but did not speak during the brief hearing, according to ABC News.
Ms Gardner is being represented by Jose Baez, who previously defended Casey Anthony and former New England Patriots tight end Aaron Hernandez. He entered a not-guilty plea on her behalf.
She has denied any involvement in Mr Bridegan's death.
"Any time divorce comes into any situation it's messy," she told WJAX in 2022 following Mr Bridegan's murder. "Even though we didn't always get along, he was still the father of my kids."
Kristen Bridegan, Mr Bridegan's second wife, said she had long suspected that Ms Gardner was behind the ambush.
"From very, very early on, everything in my body and soul told me she was behind it," she said during a news conference in August after Ms Gardner was indicted.
Ms Gardner's partner, Mr Saldana, has also pleaded not guilty.
He is accused of hiring his tenant, Henry Tenon, to ambush and kill Mr Bridegan on behalf of Ms Gardner, who was in the midst of a years-long, bitter divorce with the tech executive.
Mr Tenon reportedly admitted his role in the plot to investigators and has pleaded guilty to second-degree murder. He is cooperating with the investigation.
The state is seeking the death penalty for both Ms Gardner and Mr Saldana.
The couple will be tried together, and their trial is expected to begin on 13 April 2024.