His signature means that the club will have the option to bookend its back division with two giant (6'4") wingers from the current all-time RaboDirect PRO12 top try-scoring chart, with Walker's 36 tries placing him three spots behind soon-to-be teammate Tim Visser, who shares the top spot with Irishman Tommy Bowe (48 tries).
Speaking on his transfer, Walker said: "I've thoroughly enjoyed my time playing outside of Scotland but I've always had a burning desire to return north, so when the opportunity came to sign for Edinburgh Rugby I grabbed it with both hands.
"The club have some real quality players in the squad and I believe that together we can build a strong future and compete with the top teams on the domestic and European stage.
"Personally, as a winger, I'm looking forward to joining up with some of the championship's most dangerous play-makers and finishers. I can't wait for next season to start."
Born in Aberdeen and raised in the Borders, the former Hawick High School pupil represented Scotland at every age-grade, and helped Hawick complete a domestic double, before joining the Border Reivers in 2002.
He made his international debut in the Autumn Tests against Romania later that year and scored his first try for Scotland a week later in the 21-6 triumph over South Africa, his selection a reward for running in 11 tries for the Borders up to that point in the season.
After signing for Ospreys in 2006, a series of consistently strong performances en route to his first championship triumph earned him a replacement appearance in the 21-9 win against Wales at Murrayfield in February 2007, before scoring an early try against France in Paris the following month.
He scored in each of Scotland's Autumn Test victories over Canada (2008) and Samoa (2010) at Pittodrie, and brought the curtain down on Scotland's 2011 RBS 6 Nations with his sixth international try in the 21-8 victory over Italy, before taking the PRO12 title with Ospreys for the second time.
His form made him a stick-on for the 2011 Rugby World Cup squad but a knee injury in the final EMC Test against Italy enforced a season out of action, and limited game-time with new club Worcester Warriors.
Walker did however come back into the frame earlier this year, ending a two-year international absence with selection in the RBS 6 Nations training squad and starting for Scotland A in the win over England Saxons at Kingston Park (13-9).
He added: "Being passionate Scots, my family are delighted that we're moving home to Scotland where I still have a strong desire to represent my country, something I can achieve by earning selection and performing for Edinburgh Rugby."
Edinburgh Rugby managing director Craig Docherty, said: "We're delighted to welcome another top Scottish talent on to the playing roster at Edinburgh Rugby.
"Nikki [Walker] has an established try-scoring pedigree and brings a wealth of experience, having consistently delivered top class performances throughout his club and international career.
"It was fantastic to see him back in action for Scotland A recently and I believe that we'll see the best of him at Murrayfield next season."
Nikki Walker, 31 (wing)
Weight: 16st 10lb Height: 6ft 4in
D.O.B. 5.3.82 (in Aberdeen)
International honours: 24 caps (Scotland), 6 tries
Senior rugby career:
Border Reivers (2002-2006): Appearances 68 (67 + 1), 27 tries
Ospreys (2006-2011): Appearances 93 (77 + 16), 32 tries
Worcester Warriors (2011-2013): Appearances 11 (10 + 1), 4 tries
63x46.png){kind=logo}