The first player to be sent off at Wembley was Branko Stanovic, (wrong, see below) who was playing for Yugoslavia against Sweden in August 1948 during the Olympic Games soccer tournament. (Source: "News of the World" Football Annual 2006-2007, page 386.)
The News of the World has got it wrong again! According to the FIFA website, there were only three sendings off at the 1948 Olympic Tournament (2 Turkish and 1 Austrian) and these teams did not play at Wembley - see link - http://www.fifa.com/tournaments/archive/tournament=512/edition=197049/statistics/index.html (Only the semis, bronze play off and final matches were played at Wembley)
Unfortunately, I don't know who was the first player to be sent off at Wembley, but my guess would be Antonio Rattin who was playing for Argentina against England in the quarter final of the 1966 World Cup.
Incidentally, the first player to be sent off in a Wembley final was not Kevin Moran (1985) but Syd Hynes(playing for Leeds versus Leigh, 1971 Rugby League Challenge Cup Final).
Justin Edinburgh
bill logie
Carlos Caszely of Chile was the first player to be sent off with a red card in a World Cup match. He was sent off in 1974 fifa world cup.
gazal
Sani Kaita.
Nicolas Lodeiro (Uruguay)
Roy Aitken of Celtic
1998
1958 ya baby
A red card is shown to a player to indicate they are being sent-off. A sent-off player may not be substituted for.
Kevin Moran, for Man Utd against Everton in 1985.
A player may be sent off for using offensive, insulting, or abusive language [toward anyone].