Video footage captured by a bystander and released to the media showed a group of Chelsea supporters apparently preventing a commuter, widely identified as Souleymane S, from boarding a train. The group could be heard chanting "we're racist, we're racist and that's the way we like it".
The incident overshadowed the 1-1 UEFA Champions League draw between Chelsea and Paris Saint-Germain and has been widely condemned.
And, writing in the match programme for Saturday's Premier League clash with Burnley - the club's annual 'Game for Equality' - Terry expressed his view.
"Football is a sport for everyone, that is one of the main reasons why we love it, and what happened on the Paris Metro was unacceptable," he wrote.
"The club has reacted quickly to deal with the situation and will continue to do so."
In 2012, Terry was given a four-match ban by the Football Association and fined £220,000 after being found guilty of racially abusing QPR defender Anton Ferdinand - although a court had earlier cleared him of any criminal offence.
Also writing in Saturday's match programme, Chelsea chairman Bruce Buck insisted the club will continue to work hard to eradicate discrimination.
"Tuesday night was a crossroads for us. Despite there only being a small group of individuals involved, it showed there is still work to be done to eradicate discrimination - in all its forms," he wrote.
"We are determined to do all we can to wipe it out."
