The British thespian, best known for his stage roles and his turn as Andie MacDowell's Scottish husband in Four Weddings And A Funeral, died last week (06Apr10), aged 70.
The West End's most influential names turned out to pay their last respects to Redgrave at the service in London's Convent Garden, with the mourners giving a final standing ovation to the actor as his hearse arrived at the church.
Redgrave's university pals McKellen and theatre director Nunn gave speeches to the assembled mourners, while his sister Vanessa read from William Shakespeare's Antony And Cleopatra.
Also in attendance was Redgrave's niece, Nip/Tuck actress Joely Richardson and her brother-in-law Liam Neeson, whose wife Natasha Richardson died after skiing accident last year (Mar10).
The cause of Redgrave's death has not been confirmed, but the actor suffered ill health for several years. He was diagnosed with prostate cancer in 2000 and suffered a major heart attack in 2005.