The answer to this question depends on how you define "disciple" and what you consider the time frame to be. Here's a breakdown of the common interpretations:
* The Twelve Apostles: If you consider the original twelve apostles (minus Judas Iscariot, who betrayed Jesus and was replaced by Matthias), then Matthias could be considered the last apostle chosen in that group. He was selected by lot to fill the vacancy left by Judas.
* Apostles Beyond the Twelve: The term "apostle" (meaning "sent one") isn't exclusively limited to the original twelve. Paul the Apostle, for example, wasn't one of the original twelve, but he became a prominent apostle through his conversion experience and missionary work. In this broader sense, it's harder to pinpoint a single "last" apostle.
* Disciples in General: If you use "disciple" in the general sense of a follower of Jesus, then it's impossible to name the last one. People have continued to become disciples of Jesus throughout history, and this continues today.
* The Beloved Disciple: There is the anonymous figure in the Gospel of John referred to as the "Beloved Disciple". Some traditions hold that this refers to the Apostle John, and it is possible that he outlived the other Apostles.
In summary, if you're looking for the last person specifically added to the original group of twelve, it would be Matthias. However, the broader concept of discipleship means there isn't a single "last disciple."