Altidore briefly revealed on Friday that a deal had been done before removing the confirmation from his personal website.
However, it appears there has been no late hitch and the United States international will now fly into Wearside on Monday to complete his move.
The 23-year-old spent time on loan in the Premier League with Hull City back in 2009/10, scoring one goal in 28 appearances.
However, his reputation has blossomed since then and the powerful player registered 31 goals for the Dutch club in all competitions last season.
His arrival is just the latest in a series of acquisitions by manager Paolo Di Canio as he looks to overhaul a squad he inherited from Martin O'Neill.
The Black Cats unveiled Bosman free signings Valentin Roberge, Cabral and Modibo Diakite last week having also added youngsters Duncan Watmore and David Moberg Karlsson to the mix, and the Italian has a series of other targets in his sights.
However, the striking department is a priority, with Steven Fletcher having to carry much of the burden last season before injury struck, and Di Canio will hope the American is the man to provide the support.
January signing Danny Graham has to date been unable to contribute on the goals front, while Connor Wickham and Ji Dong-won have struggled to make an impression and Stephane Sessegnon's future remains uncertain.