Sinclair, who played under Clarke at both Salisbury City and Bristol Rovers, spent the last five years playing at the Memorial Ground - making over 160 first-team appearances - is excited about the future and keen to do all he can to help his new club to get back to form.
The 31-year-old, who won several promotions alongside manager Darrell Clarke, is keen to meet and get to know the Saddlers supporters as he feels it is important for them to know they can rely on him to do all he can for the cause.
Speaking via the club's official website, Stuart said; "It’s exciting times. It has been a tough period for the club but now it’s all about getting that excitement back and moving forward and being successful.
"I was at Bristol Rovers for a long time and I enjoyed a successful period with them. It’s a new challenge now and that is exciting. It’s a great club and I can’t wait to meet the supporters and everybody at the club.
"I have a close relationship with the gaffer and I know what he can bring to the table. I can trust him and that is important for me personally. When he told me about things here at Walsall, I was extremely excited.
"I’m an honest and energetic kind of player and I will do everything I can to help us win football games. That’s what I have tried to put forward in my footballing career so hopefully, that will come across to the supporters."