Suárez was Spain's first democratically elected prime minister since the Second Spanish Republic and a key figure in the country's transition to democracy after the dictatorship of Francisco Franco.

When Spain was still an autocratic regime, he was appointed prime minister by King Juan Carlos in 1976, hoping that his government could bring about democracy.

[2][8] Within a year of his appointment, Suárez had rapidly introduced reform measures and taken decisive steps in Spain's transition to democracy (La Transición).

The Political Reform Act, which permitted universal suffrage and established the basis for a new, bicameral parliament, was passed by a huge majority in the Francoist Cortes in November 1976 and overwhelmingly approved by a referendum in December.

[9] The legalisation of the PCE in particular provoked fury in the Spanish military; Suárez responded by sacking hardliners and promoting more liberal officers such as Manuel Gutiérrez Mellado.

[9] In an effort to address separatist tensions and calls for increased local autonomy, Suárez also negotiated the creation of Spain's autonomous communities.

[6] Suárez's political power eroded as he struggled to deal with economic recession, mounting violent activity by ETA, calls for further regional autonomy and divisions within his own party.

[6] In January 1981, trailing in the polls behind the PSOE and faced with a revolt within the UCD, Suárez announced his resignation as prime minister.

[2] A month later, as parliament took the vote to confirm Suárez's successor Leopoldo Calvo-Sotelo, Lieutenant-Colonel Antonio Tejero and around 200 Civil Guards stormed the chamber in an attempted coup and held the lawmakers hostage for some 22 hours.

Meanwhile, promised military support for the coup failed to materialise – with few exceptions, most notably Jaime Milans del Bosch who led pro-coup troops in Valencia.

Suárez was awarded the Príncipe de Asturias a la Concordia in September 1996 for his role in Spain's early democracy.

On 8 June 2007, during the celebration of the 30th anniversary of the first democratic elections, King Juan Carlos appointed Suárez the 1,193rd Knight of the Order of the Golden Fleece.

[15] Pope Francis shared his condolences, saying: "In fraternal suffrage with you all, I make fervent prayers to the Lord for the eternal rest of this esteemed and feature figure of the recent history of Spain.

[18] Their eldest daughter, María del Amparo ("Mariam") Suárez Illana (1962–2004), died of breast cancer on 6 March 2004, following an 11-year illness.