The former England captain attended an investiture ceremony at Windsor Castle, marking a moment that cements his position among the nation's most celebrated sporting figures.
Beckham, 50, was accompanied by his family as he received the title of "Sir David" more than two decades after being awarded an OBE in 2003.
His knighthood recognises not only a decorated football career but also years of charitable work, including his long-standing role as a UNICEF Goodwill Ambassador and his recent appointment as an ambassador for The King's Foundation.
Speaking after the ceremony, Beckham told PA: "Growing up in East London with parents and grandparents who were so patriotic and proud to be British, I never could have imagined I would receive such a truly humbling honour.
"To have played for and captained my country was the greatest privilege of my career and literally a boyhood dream come true."
Beckham's storied career
Beckham's football journey is among the most distinguished of his generation. Rising through Manchester United's famed 'Class of 92', he won six Premier League titles, two FA Cups, and the 1999 Champions League, helping the club secure an iconic treble.
He later played for Real Madrid, LA Galaxy, AC Milan and Paris Saint-Germain, before retiring in 2013.
Internationally, Beckham earned 115 caps for England, 59 as captain, and was renowned for his leadership and set-piece brilliance.
His famous stoppage-time free-kick against Greece in 2001, which secured England's place at the 2002 World Cup, remains one of the defining moments in modern English football history.
Charity work and global fame
Off the pitch, Beckham has been equally influential.
Since 2005, he has worked with UNICEF on initiatives supporting children's health and education, and he has used his platform to champion community and youth programmes across the UK.
His involvement in London's successful 2012 Olympic bid and the ongoing development of Inter Miami CF in the United States also highlight his broader impact on the global game.
The honour arrives after years of speculation over when the former midfielder might receive a knighthood, including an embarrassing PR disaster after leaked emails revealed the star's frustrations at being overlooked in 2017.
The Football Association issued congratulations following the announcement, calling Beckham's knighthood "a fitting tribute to one of England's greatest players and most dedicated servants to the game".
Beckham joins a distinguished list of British football figures to have been knighted, including Sir Bobby Charlton, Sir Geoff Hurst and Sir Kenny Dalglish.