It will be our second appearance at the Essex coastal ground in 17 days, following our friendly with the Shrimpers on Tuesday, July 23 (7.45pm).
Vitesse are ranked the fourth biggest club in the Netherlands - behind champions PSV Eindhoven, Feyenoord and Ajax - but they just missed out on European football next season by a whisker.
A 2-2 draw in their final game of last season, against Sparta Rotterdam, meant they could only finish equal fourth in the eredivisie (Dutch First Division) on points - but ended up placed sixth (behind Roda and Utrecht) on goal difference.
But Vitesse, eight times UEFA Cup qualifiers, are recognised as one of the most go-ahead clubs in Europe, boasting a retractable pitch at their futuristic Gelredome arena, where rock concerts and other big events are also held.
The reason behind the decision to play the game at Southend is to allow the new Upton Park pitch a little extra time to bed in and to ensure it is in tip-top condition for the start of the new Premiership season on August 24, and throughout the winter months.
Tickets for the game against Vitesse go on sale from Monday, July 22, priced at £15 alongside the pitch; £10 behind the goals; while concessions for all areas will be £5. They will be available from the West Ham United Ticket Office on 020 8548 2700.
Our Ticket Office is already selling tickets for the friendly between Southend United and the Hammers on July 23, priced £15 for adults and £10 for under-16s/OAPs.