The 25-year-old joined Wolves in 2010 from Burnley for a club record ?7million fee and he has hit double figures in both his Premier League campaigns with the club.
But following relegation, he appears determined to return to the top flight, with Sunderland bidding for his services.
The Black Cats have had a couple of offers rejected this month, and this has now prompted Fletcher to make his decision - which he revealed via his Twitter account.
He wrote: "Just handed in a transfer request just to let the fans know where I am at right now.... #headsgone."
Wolves have confirmed Fletcher's request but will not sell the player until the club's valuation of the 25-year-old is met by any interested clubs.
A statement from the club read: "Wolves can confirm that Steven Fletcher has handed in an official transfer request.
"The player's frustration stems from the fact that several bids have been rejected for his services, none of which meets the club's valuation.
"As previously stated, no player will leave Wolves unless the club's valuation is met.
"Wolves will be making no further comment at this time."
Fletcher joined Wolves in June 2010 from Burnley, signing a four-year contract with an option for a fifth year.
The Scottish international made 26 Premier League starts last season, scoring 12 top flight goals. Fletcher has not played in any of Wolves' pre-season games for the past two weeks because of an ankle injury.
Wolves also sold winger Michael Kightly to Stoke on Wednesday, while defender Christophe Berra asked to leave last week.
Liverpool are also interested in goalkeeper Dorus De Vries, who played under Reds boss Brendan Rodgers at Swansea.
