Browning becomes the Black Cats' second signing of the summer following the arrival of former Everton team-mate Brendan Galloway.
The 23-year-old, who can operate as a right-back or central defender, will be working under Simon Grayson for the second time after playing under him at Preston North End last season.
After making his Everton debut in September 2014, a 1-1 draw against Liverpool at Anfield, Browning has made a further eight appearances for the blue half of Merseyside.
In January 2017, Grayson brought Browning to Deepdale where the youngster helped Grayson’s Preston to an 11th-placed finish in the Sky Bet Championship – making eight appearances for the Lilywhites.
Browning could make his uncompetitive Sunderland debut in Sunday’s friendly against Scottish Premiership side Hibernian.
Browning has his say on Sunderland move
Speaking to safc.com, Browning said he is "delighted" to have joined Sunderland and "can’t wait to prove a point" with the season drawing ever closer.
The Liverpool-born player revealed he is "excited" to meet new faces and it is "helpful" that he already personally knows several members of the Sunderland squad.
Galloway, Darron Gibson and Bryan Oviedo will all be familiar faces to Browning, players who he played alongside at Everton.
Browning is also friendly with Duncan Watmore having played with the winger for England under-21s.
Following his arrival on Wearside, Browning described Sunderland as a "big club" with a "lot of fans."
"Hard-working" was the word echoed by Browning when asked what Sunderland fans can expect to see from their new man.
Will Browning get a chance to shine?
Undoubtedly, Browning will get his chance to impress at the Stadium of Light.
Grayson’s first game in charge of Sunderland against Bury on Friday night saw several youngsters given a starting berth.
Luke Molyneux, Rees Greenwood, Josh Maja, Tom Robson, Ethan Robson, Michael Ledger, Denver Hume and Owen Gamble all featured as Sunderland came from 2-0 behind to win their first pre-season friendly 3-2 away from home.