Beverly Smith, National President and CEO of Delta Sigma Theta, tells TMZ ... the 108-year-old organization is already planning a special memorial service to honor the veteran stage and TV actress who recently passed away.

We're told the service Suzzanne's getting is called the Omega Omega service ... which is a final rite of passage and farewell service for the sorority's sisters. The org, BTW, is an historically Black sorority whose notable members include Barack Obama's former U.S. Attorney General Loretta Lynch and Atlanta Mayor Keisha Lance Bottoms.

While most members have their Omega Omega service held at the local level ... we're told Suzzanne's service will be a nationwide celebration of her life and similar to its memorials for Aretha Franklin and Cicely Tyson.

Former national presidents and leaders for the sorority will be present. It'll be open to the public ... though the org's still trying to figure out where the event will be held.

For those who can't make it, we're told there will be a live stream. Cicely's live stream drew upwards of 30k viewers.

The sorority clearly meant a lot to Suzzanne. She was inducted into honorary membership in 2004 and served as Honorary Co-Chair of the National Arts & Letters Commission from 2013 to 2017. She was active in local, regional and national initiatives since her induction.

As we reported ... Suzzanne -- best known as the matriarch in the WB sitcom "The Parent 'Hood" and who recently appeared in the Netflix series "When They See Us" -- died from complications of cancer.