Deputy President Cyril Ramaphosa‚ former African Union chairperson Nkosazana Dlamini-Zuma and former first lady Zanele Mbeki are among the crowds.
ANC veteran Winnie Madikizela-Mandela took her seat a short while ago next to Economic Freedom Fighters (EFF) leader Julius Malema.
Ramaphosa is leading the government delegation to the funeral and memorial service.
An open grave near the entrance of the cemetery grounds has been allocated for Kathrada’s burial.
The 86-year-old died on Tuesday morning after suffering a blood clot to the brain.
President Jacob Zuma will not attend the funeral‚ in accordance with the family’s wishes‚ the presidency said earlier on Wednesday.
Zuma said a cabinet meeting had been postponed to later in the afternoon to accommodate ministers attending the funeral.
