Bonnie Lu Nettles (née Trousdale; August 29, 1927 – June 19, 1985), later known as Ti (/tiː/; TEE), was co-founder and co-leader with Marshall Applewhite of the Heaven's Gate new religious movement.

Nettles died of melanoma metastatic to the liver in 1985 in Dallas, Texas, twelve years before the group's mass suicide in March 1997.

In his writings, Applewhite claimed to have been "visiting a hospitalized friend when Mrs. Nettles entered the room and their eyes locked in a shared recognition of esoteric secrets."

Terrie Nettles, Bonnie's daughter, worked at a theater where Applewhite produced weekend children's shows and taught in an in-house drama school.

Nettles' three youngest children were left to remain with their father, while her oldest daughter, Terrie, then aged 20 and skeptical of her mother's ideas, fended for herself.

In 1983, she had to have an eye removed due to cancer, and her doctor informed her that the disease was already spreading through the rest of her body.

[6] Applewhite and Nettles went by the collective of "The Two", as well as the singular names "Bo" and "Peep" respectively[7] and later "Do" and "Ti",[1] along with "Guinea" and "Pig" at some points in time.