Three On Stamps.3!

Spain,1999
Athletics World Championships in Sevilla
Long jump + Hurdles race + Javelin throw

Here are Professor Geiger's designs for the "Miners" and "Mowers" stamps of Germany's 1917-23 inflationary period. The first two designs began use in the 1921 "Number, Laborer, Posthorn and Ploughman" definitive series. These two designs were used again in 1922-3 on mark-valued definitives, but the chisel and pick wielding miners on these stamps are shown facing left.

Italy,2020
Biathlon World Championships in Antholz-Anterselva

This 5c value (Sc #1026) from Nicaragua's September 7, 1976 "Montreal Summer Olympic Games" set depicts the 1952 Helsinki Olympics, gold medal-winning, French coxed-pair rowing team. Depicted are coxswain Bernard Malivoire with rowers Raymond Salles and Gaston Mercier.

Wallis & Futuna,2003
100 years since the death of French painter Paul Gauguin ( joint issue with New Caledonia )
"A sketch of tahitian faces"

On November 12, 1962 the Netherlands issued a set of five Child Welfare stamps which depict children engaged in everyday activities. The 30c + 9c value (Sc #B372) depicts three children making music.

Monaco,2017
Homage to Grace Kelly (1929-1982),an American actress who became Princess of Monaco.
This stamp shows a poster of "High Noon" (1952),directed by Fred Zinnemann and starring Gary Cooper,Grace Kelly and Katy Jurado.
In France the name of this movie was "Le train sifflera trois fois" (the train will whistle three times)

Wallis & Futuna,2016
Fight against diabetes.
"Eat better and move more to protect your health"

In Slavic mythology, Sudicka ("Fates") are three women spinners that meted out fortune, destiny, judgment and in some cases, fatality, when a child was born. The story has many similarities to the Greek myth of the Moirai.

Slovenia - 2004:

How is that not four?

the legend is about "The Three fates", so I believe it fits this collection. If not, I appreciate if one of the moderators will delete this post.

This June 27, 1966 French one franc stamp (Sc #1150) is from the "Paintings 1966" series. Stamp depicts George de la Tour's (1593-1652) Le Nouveau-ne' (Eng: The New-born) of 1645-8. Painting is in the Museum of Fine Arts, Rennes.

Because of the subject, this painting is often thought of as a Nativity scene.

Wallis & Futuna,2007 and 2016
Traditional dances

The three Charites (Roman: Graces), daughters of Zeus and Eurynome, are goddesses of charm, beauty, creativity and fertility. Their names are: Aglaea (Beuty), Euphrosyne (Mirth) and Thalia (Good Cheer). They were responsible for the god meals and created a good atmosphere in celebrations. Usually, they were constant companions of Aphrodite (Venus), goddess of beauty and love.

Here are five stamps show the Three Graces in different paintings:

The Three Graces on 1st century fresco from Pompeii – Guinea Equatorial:

The Three Graces, by Hans von Aachen (1552-1615) – Romania, 1969:

The Three Graces" by Peter Paul Rubens (1577-1640) – Upper Volta, 1977:

The three Graces, painting by Raphael (1483–1520), issued by Bulgaria on December 28, 1984:

The three Graces, by Battista Naldini (1535–1591), issued by Hungary on December 10, 1968:

Of course, the most famous painting of the Three Graces is the La Primavera by Botticelli mentioned by jleb1979 in page 3 of this thread with two examples. I will bring more from Botticelli other time.

On March 1, 1995 Finland issued a horizontally se-tenant pair of 2.40 +.60 markka "Pro Filatelia" charity stamps depicting paintings by Albert Edelfelt (1854-1905). One of the stamps (Facit #1289), shown here, features Edelfelt's 1884 oil painting Boys Playing on the Lakeshore.