Flags On Stamps.......new Additions !

Croatia
25th Anniversary of The Croatian State
June 23, 2016
The stamp shows a flying national flag of Croatia.

Norway
Flag of Norway Bicentenary
November 5, 2021
National flag of Norway

This 2022 US Flag issue will be available on January 9.

Luxembourg
50th Anniversary of the Luxembourg Flag
April 27, 2022
The minisheet was printed with lenticular film.

The postage stamp "25th Anniversary of the USA and Ukraine Diplomatic Relations" (2017) features two flags

1996 Spain
Mapa oficial del Estado Autonómico
Edifil 3460

On 5 December 1996, Spain issued a sheetlet containing a single stamp with the official map of the Spanish autonomous state. Spain has 17 autonomous communities and two autonomous cities. Next to the official map of the autonomies appear the national flag of Spain and the flags of the autonomous communities. The flags of the autonomous cities Ceuta and Melilla appear near the respective North-African exclaves. In addition to the flags depicted on the stamps, the state flag of Spain is depicted in the margin of the souvenir sheet.


1996, España / Spain, Official Map of the Autonomous State, Edifil 3460

At the top of the frame to the left of the map is the flag of Spain. Below it, from top to bottom, left to right, the seventeen flags of the autonomous communities that appear in alphabetical order are:
Andalusia and Aragon,
Principality of Asturias and Balearic Isles,
Canary Isles and Cantabria,
Castile and León and Castile - La Mancha,
Catalonia and Extremadura,
Galicia and Community of Madrid,
Murcia Region and Chartered Community of Navarre,
Basque Country and La Rioja, and
Valencian Community.

The Fábrica Nacional de Moneda y Timbre printed 1,200,000 miniature sheets.

Principat d'Andorra
18 January 2021
Correus espanyols (Spanish posts)
Serie básica, inland tariff to Spain though Spanish posts in Andorra
Edifil nr. 507

During WWII, the USA issued the Overrun Countries series, a series of thirteen stamps issued in 1943 and 1944 as a tribute to thirteen nations overrun, occupied, and/or annexed by the Axis Powers during World War II.

The stamps have same engraved frame and each stamp has different flag printed by photogravure. Here are three in HR for examles:

Betsy Ross (1752-1836), was an American upholsterer who was credited by her relatives in 1870 with making the first American flag, accordingly known as the Betsy Ross flag. Though most historians dismiss the story, Ross family tradition holds that General George Washington, commander-in-chief of the Continental Army and two members of a congressional committee—Robert Morris and George Ros visited Mrs. Ross in 1776 and she presented them the first American flag.

Mrs. Ross presenting the flag to Washington, Morris and Ros, painting by Charles H. Weisberger, issued by USA on January 1, 1952 to commemorate the 200th anniversary of Ross birth:

Spain
Independence of Central America Bicentenary
September 15, 2022
The stamp shows flags of Guatemala, Honduras, El Salvador, Nicaragua, and Costa Rica.

This 2022 stamp celebrates 25th Anniversary of Georgia - Ireland Diplomatic Relations.

Mexico - Portugal Diplomatic Relations
June 6, 2014
The design show the flags of the two nations.

This India 2022 stamp marks the 75th anniversary of the National Flag.

Tunisia
Independence Day
March 20, 2022
The stamp shows the national flag of Tunisia.

Estonia
Centenary of Diplomatic Relations with the United States
June 17, 2022
The stamp depicts flags of the two nations.