The announcement was made over the weekend by Jewett on the website for Giving Pledge, the movement created by Bill and Melinda Gates and Warren Buffett to encourage extremely wealthy people to contribute a majority of their wealth to philanthropic causes.
While Scott gave away almost $6 billion last year, Jewett said that he also plans to give away the majority of his wealth during his lifetime.
"And now, in a stroke of happy coincidence, I am married to one of the most generous and kind people I know -- and joining her in a commitment to pass on an enormous financial wealth to serve others," Jewett said in the note, announcing the marriage.
With a net worth of $53.5 billion, Scott, 50, is the world's 22nd-richest person, according to the Bloomberg Billionaires Index.
Since her divorce with the Amazon founder in 2019, she has made tremendous contributions to philanthropic causes.
Bezos made a $38 billion divorce settlement -- now worth considerably more -- with MacKenzie who has since changed her surname to Scott.
"I have seen many ways that MacKenzie has seen her efforts enhanced when she acts on the belief that those with common values but different perspectives, strengths, and experiences are essential to effecting positive change," Jewett said.
"We are united in that understanding and in our excitement for all we have to learn from so many people working in service of others. With that as a foundation, I join with the kindest and most thoughtful person I know in making this pledge, grateful for the exceptional privilege it will be to partner in giving away assets with the potential to do so much good when shared."