The season continues to follow Jefferson, now a high school principal in his second stint as the superhero Black Lightning, as he fights against local corruption in his community of Freeland.

Cress Williams stars as Jefferson, along with principal cast members China Anne McClain, Nafessa Williams, Marvin "Krondon" Jones III, Christine Adams, Jordan Calloway, and James Remar also returning from previous seasons.

On the early renewal of Black Lightning as well as other series, network president Mark Pedowitz released a statement reading, "These early orders for next season give our production teams a head start in plotting out story arcs and a jump on hiring staff, and this also provides us with a strong foundation of established, fan-favorite CW shows to build on for next season.

[15] Main cast members Cress Williams, China Anne McClain, Nafessa Williams, Christine Adams, Marvin "Krondon" Jones III, Jordan Calloway, and James Remar return from previous seasons as Jefferson Pierce / Black Lightning, Jennifer Pierce / Lightning, Anissa Pierce / Thunder, Lynn Stewart, Tobias Whale, Khalil Payne / Painkiller, and Peter Gambi, respectively.

In November 2020, Chantal Thuy, who portrays Grace Choi, was promoted to a series regular for the fourth season.