Ilirra Deel was a Betazoid female who worked for Starfleet Intelligence in the 24th century. Deel was considered an extremely gifted telepath, even for a Betazoid.

In the mid 2380s she worked as SI's liaison to Sarina Douglas. Douglas considered Deel to be a friend. Deel trained Douglas to be receptive to telepathic communication from her, and taught her how to create mental messages that Deel could read.

The pair would arrange clandestine meetings by encoding messages in anonymous personals. While Deel favored straightforward disguises, Douglas liked to make her friend dress in more elaborate disguises. At one such meeting Douglas arranged for Deel to disguise herself as an Orion female wearing a latex bodysuit along with thigh high boots and a short imitation leather jacket. This led Deel to remark that she looked like a socialator.

The pair arranged a meeting in January 2386 in which Douglas reported on her efforts to infiltrate Julian Bashir into Section 31. Douglas reported that Section 31 agent Cole had made an overture to Bashir recently. Deel asked Douglas to make sure that Bashir was infiltrated into the organization while Section 31 was interested, unsure of how long Section 31 would remain interested in recruiting Bashir into the organization. (ST - Section 31 novel: Disavowed)