Born with a silver spoon in one's mouth
Born into a wealthy family.
This is commonly thought to be an English phrase and to refer to the British aristocracy. That may well be the case, but the earliest citation in print is from the USA.
Deb. U.S. Congress, 1801:
"It was a common proverb that few lawyers were born with silver spoons in their mouths."
Mediaeval spoons were usually made of wood. Spoon was also the name of a chip or splinter of wood and it is likely that is how the table utensils derived their name. It has been a tradition in many countries for wealthy godparents to give a silver spoon to their godchildren at christening ceremonies. That may be the source of the phrase, or it may simply be derived from the fact that wealthy people ate from silver while others didn't.
In the keynote speech to the US Democratic National Convention in 1988, the Texas State Treasurer Ann Richards modified the proverb at the expense of the well-born and wealthy George Bush:
"Poor George, he can't help it - he was born with a silver foot in his mouth."