The centre-half rejected a new deal at the Recreation Ground and has signed a two-year contract at Adams Park.
Wanderers boss Gary Waddock is familiar with Winfield, after his time as Aldershot manager.
He told the club website: "He's a big strong centre-half with an excellent attitude and willingness to learn.
"He's extremely professional and always conducts himself superbly on and off the pitch."
Winfield amassed 93 appearances while at the Recreation Ground, scoring five goals, and also made four appearances for Salisbury during a loan spell in January 2009.
"It always helps when you know people at a club, it breaks the ice," he said.
"The manager knows what to expect from me and vice versa, so it's comfortable."
Source: BBC Sport
Source: BBC Sport