Trumpeters of the Life Guards regiment heralded installation of the first fountain in Kensington Gardens and around half-a-dozen are due to go into each of the other seven parks.
An international competition singled out two designs and was funded by US charity the Tiffany & Co Foundation.
Architect Ben Addy designed the Trumpet. The other, Watering Holes by Robin Monotti and Mark Titman, will be made for Green Park this spring.
A competition spokeswoman said: "Most drinking fountains resemble mini urinals. We thought it was time to add beauty into the mix."