Sir Patrick played Picard from 1987 through to 2002 and contributed significantly to the character's air of wisdom and brooding with his commanding presence as a Shakespearean actor.
It is not yet clear in what form Jean-Luc Picard will be reprised, although there was a new series announced in June which will tell the story of the next chapter of Picard's life.
Announcing his return to the role in a statement on Twitter, the actor wrote: "I will always be very proud to have been a part of Star Trek: The Next Generation, but when we wrapped that final movie in the spring of 2002, I truly felt my time with Star Trek had run its natural course.
"It is, therefore, an unexpected but delightful surprise to find myself excited and invigorated to be returning to Jean-Luc Picard and to explore new dimensions within him.
"Seeking out new life for him, when I thought that life was over."
Sir Patrick, who is an outspoken critic of the UK leaving the EU, declared in April that he believes Jean-Luc Picard would be anti-Brexit.
In his latest tweet, Sir Patrick spoke about his connection with Picard.
"During these past years, it has been humbling to hear stories about how The Next Generation brought people comfort, saw them through difficult periods in their lives or how the example of Jean-Luc inspired so many to follow in his footsteps, pursuing science, exploration and leadership.
"I feel I'm ready to return to him for the same reason - to research and experience what comforting and reforming light he might shine on these often very dark times.
"I look forward to working with our brilliant creative team as we endeavour to bring a fresh, unexpected and pertinent story to life once more."