For additional meanings of "Ellison", please see Ellison.
The Ellison was a late 24th century transport.
On May 12, 2396, the Ellison departed Earth for the Beta Quadrant. She was carrying passengers. Soji Asha claimed to be one of those passengers, but Narek claimed his research showed her name was not on the passenger manifest that day. (PIC: "Absolute Candor")
This transport was only mentioned in dialogue.
Star Trek: Picard co-producers Akiva Goldsman and Michael Chabon confirmed in a video made for WIRED magazine that the Ellison was named for Harlan Ellison. [1]