The Righteous Gemstones · A Viewer's Companion
Everyone in this show is loud, blond-ish, and named confusingly on purpose: there are two Aimee-Leighs, a Baby Billy and a BJ who are different people, and a Kelvin, a Keefe, and a Karl. This chart untangles it by blood: cream borders are Gemstone blood, pink is the Freeman side — the dead matriarch Aimee-Leigh's showbiz family, which is how Baby Billy is the kids' actual uncle — and teal is everyone who married (or prayed) their way in.
The Gemstones aren't at war with another house — they're at war with the org chart. Four facts explain most of it.
The show's most-forgotten fact: Baby Billy Freeman is Aimee-Leigh's older brother — her childhood duet partner from their tent-revival days. That makes him Jesse, Judy, and Kelvin's blood uncle, which is the only reason the family keeps bankrolling his schemes: Baby Billy's Bible Bonkers, the Teenjus TV pitch, and a lifetime of skimming the collection plate.
May-May is Eli's sister, frozen out of the empire decades ago. She married Peter, a preacher turned doomsday-militia man who, in Season 3, kidnaps his own sons — gentle giant Karl and true-believer Chuck — into his Brothers of Tomorrow's Fires. So the camo-wearing hostage-takers are Jesse, Judy, and Kelvin's first cousins.
Eli built it, Aimee-Leigh made it beloved — and when Eli steps back, he hands it to all three kids at once. The trio nearly bankrupts the ministry in Season 3 before clawing it back; by Season 4 Jesse plays CEO, Judy runs the show onstage, and Kelvin's ministries out-poll them both. Meanwhile grandson Gideon quietly becomes the most competent Gemstone alive.
Keefe Chambers starts as Kelvin's rescued ex-Satanist "best friend" and ministry assistant — a running will-they-won't-they the show finally answers: they're a couple, they say it out loud, and by the final season Kelvin accepts his Top Christ Following Man honors with Keefe at his side, engagement included. Teal border, but family.
Each season detours into the past: Memphis 1968 (Eli's enforcer days as the "Maniac Kid"), 1993 (Baby Billy abandoning Harmon at a rest stop), 2000 (the May-May rift, young Aimee-Leigh on tour), and the Season 4 prelude in 1862, where Civil War ancestor Elijah Gemstone — a fake preacher played by Bradley Cooper — proves the grift is hereditary.
Half this cast shares initials, hair color, or an actual name. Keep these apart:
Aimee-Leigh Gemstone is Eli's late wife — dead before episode 1, alive in every flashback and everyone's guilt. Aimee-Leigh Jr. is Baby Billy and Tiffany's baby daughter, born in the Season 3 finale and named in tribute (and, being Baby Billy's, partly as brand extension).
Both grown men with "B" nicknames, zero relation. Baby Billy (Walton Goggins, white pompadour) is the kids' uncle. BJ (Tim Baltz, rollerblades) is Judy's mild-mannered husband. One steals from the family; the other just wants a nice ceremony for his baptism.
The Montgomery brothers, both bearded, both in camo. Chuck (Lukas Haas) is the leaner one who drank his father's doomsday Kool-Aid longest. Karl (Robert Oberst) is the strongman-sized one who'd rather be home with his mama.
Jesse and Amber's sons, oldest to youngest. Gideon: the Hollywood-stuntman prodigal who robbed the family in S1, then earned his way back. Pontius: bleach-blond, leopard print, allergic to consequences. Abraham: the polite young one nobody writes storylines for.
Three K-men, one couple, one cousin. Kelvin is the youngest Gemstone heir; Keefe is his partner in ministry and in life; Karl is his Montgomery cousin. If he's doing muscle worship or smashing Satanic merch, that's the Kelvin–Keefe orbit.
Eli is John Goodman, the living patriarch. Elijah is Bradley Cooper in the Season 4 prelude — the card-cheating Civil War "preacher" the family descends from. The names are one syllable apart on purpose.
The pink-vs-cream split. Freemans (Aimee-Leigh, Baby Billy, Harmon, the baby) were poor tent-revival entertainers; Gemstones are the empire Eli and Aimee-Leigh built. Baby Billy's lifelong grievance is being born into the first family and never cut into the second.

Eli's right hand and the ministry's chief of operations — the one sane adult in every room, and keeper of most Gemstone secrets.

Wrestling promoter from Eli's Memphis enforcer days, back in Season 2 with old debts and a genuine, unsettling fondness for his old pal.

Aimee-Leigh's best friend and singing partner — and Eli's Season 4 romance, which his adult children handle with all their usual grace.

Head of the rival Simkins ministry dynasty — Jesse's church-planting nemesis in the final seasons.

Technically family — the 1862 ancestor from the Season 4 prelude, a gun-toting fraud who stole a dead preacher's collar and founded the bloodline's whole business model.
A note on the portraits: these are the characters as they appear on screen — stills from the Righteous Gemstones wiki, cropped and served from this site so nothing hotlinks. Abraham keeps his initials; the wiki never got a usable solo still of him. Chart reflects the complete series, through the Season 4 (final) finale — spoilers all the way to the end.