The Black Cats have completed the signing of the South Africa international on a one-year deal.
Sunderland AFC (@SunderlandAFC) August 19, 2016
The Black Cats have wrapped up the capture of Pienaar on a free transfer after his Everton contract expired at the end of last season.
The South Africa international has penned a one-year deal after spending three weeks training with Sunderland in the hopes of gaining a new employer.
Everton's Steven Pienaar in action with Stoke City's Steven Sidwell and Geoff Cameron
His arrival will certainly ease the club's injury worries, with midfielders Seb Larsson, Jan Kirchhoff and Lee Cattermole out with injuries and Moyes' midfield looking desperately thin.
Moyes welcomed the arrival of a player he brought to, and nurtured, at Everton, and he believes he can bring the best of his players, particularly left-back Patrick Van Aanholt.
"Steven is someone who will help us keep the ball better," Moyes told the Sunderland Echo.
Sunderland manager David Moyes
"He has been a great player and he made Leighton Baines when he was at Everton and will do a lot for Pat, help him join in, get forward and get crosses in.
"If he does that job then he will be very good for Pat. "He also gives us a little bit of experience, we have just lost a few players for a bit of time.
"He is only here on a one-year contract and we will give him every opportunity to show if he is as good as he was in his early days.
"And if he is not, then we will use him for his experiences at different times."
Pienaar's arrival will definitely bolster Sunderland's creative options, with the 34-year-old's darting runs and flair on the ball catching out many a Premier League defender over the years.
The former Borussia Dortmund ace will be in contention to make his debut for his new club when Sunderland take on North East rivals Middlesbrough at the Stadium of Light on Saturday.