It was notably worn in the Sarah Jane Adventures cross-over story The Wedding Of Sarah Jane Smith (see below).
This was the last time David Tennant went before the cameras as the Tenth Doctor.
Although it was shown before his departure in The End Of Time, due to the shooting schedules on the two series, it was actually shot after the regeneration scene had been filmed.
Louise explains her colour palette for the blue suit, as well as how it was decided which episodes it would specifically appear in.
Thanks to Kevin Coppa for giving the interview clips the polished look, and enormous thanks to Louise Page for sharing her memories of dressing the Tenth Doctor with us all