At USA Sebastian was head of alternative programming and her most notable credit was Chrisley Knows Best.
At ITV America she will work at the ITV Entertainment division and report to division president David Eilenberg, who joined from Turner Broadcasting System in March.
He said: “Jessica brings immense talent, drive and expertise to ITV, having worked on both the network and producer sides of our business.
“Her experience and perspective are particularly meaningful at a time when our business is ultra-competitive but also ripe with opportunity.”
Prior to USA, Sebastian was vice president of current and development at Electus. She has worked in development at NBCU’s cable net the Style network and at Shine Endemol-owned Original Media.
Her credits include Southern Justice and the US version of Wife Swap.