In an open letter released Monday by the "Let's Stay Together" anti-independence campaign group, the former Real Madrid player said he was proud to have represented Britain as part of the team that secured the 2012 Olympics Games for London.
Beckham underlined his satisfaction at having been England's captain, noting that he felt that same "passion" when he was appointed to represent Britain in the Olympics Games.
"We worked together to bring the greatest sporting event of them all to our nation and I was thrilled to watch us competing together against the world," added Beckham, who emphasised his satisfaction at seeing Scottish athletes like Chris Hoy (cycling) and Andy Murray (tennis) win the gold medals at London 2012 Olympics Games.
However, Beckham admitted that he cannot tell the Scots how they should vote, but noted that the decision will have a huge effect on each and every citizen of Britain.
"We want to let you know how very much we value our relationship and friendship," said the former player, underlining that he was confident that the Scots would vote for the "renewal" of "historic bonds".
"What unites us is much greater than what divides us. Let's stay together," he added.
Various polls published over the weekend anticipate a narrow victory for the "No" vote in the referendum Thursday on independence.
Voters over 16 who live in Scotland will have to answer "Yes" or "No" to the question whether they want the region to be independent.