The Sexy Back pop star, now married to actress Jessica Biel, said he was sorry for speaking out of turn, or not speaking up, for what was right in the past.
“I understand that I fell short in these moments and in many others and benefited from a system that condones misogyny and racism,” he said.
Timberlake and Spears dated for about three years before splitting up abruptly in 2002. Spears was questioned in the media about her virginity while Timberlake said he had slept with her and then wrote a song Cry Me a River in which he implied that she had cheated in the relationship.
In Friday's apology, Timberlake said the entertainment industry sets white men up for success.
“Because of my ignorance, I didn't recognise it for all that it was while it was happening in my own life,” he said.
Spears' business and personal affairs have been controlled by court-appointed conservators since 2008.
Representatives for Jackson and Spears did not immediately respond to requests for comment on Friday.
Reuters