Spezia won the 1944 Campionato Alta Italia which was officially recognized by FIGC (the Italian Football Federation) in 2002 after a long dispute and the use of a special permanent badge was authorized.

In 1929 Spezia won the Prima Divisione but the league was demoted to become the third division in Italy so the team remained at the second level, playing in Serie B.

In 1944, because of World War II, the Italian football federation decided to split the top league into regional rounds.

The team, named 42° Corpo dei Vigili del Fuoco della Spezia (Firefighters of La Spezia) after a merger with the local firefighter to have a sufficient number of players, was included in Round D of Emilia-Romagna, together with Corradini Suzzara, Fidentina, Orlandi Busseto and Parma.

Following the decision of FIGC in 2002, Spezia is authorized by the Italian Federation to exhibit a tricolour badge on the official jerseys which is unique, being the only example of a permanent one in Italy.

After the war, the Italian football system once again consisted of national leagues, as opposed to regional rounds, and Spezia returned to Serie B from 1946 to 1951.

Life in Serie B with traditional Italian powerhouses Juventus, Genoa and Napoli was difficult for the newly promoted Ligurian side, which themselves were fighting to avoid the relegation spots in the 2006–07 campaign.

With a squad consisting of mid-season signing Guilherme do Prado, Tomás Guzmán, Corrado Colombo, Massimiliano Guidetti, Nicola Santoni, amongst others, Spezia managed to survive in Serie B through finishing in 19th place, gaining participation in the playout round after a late victory in Turin against Juventus.

Having tied 2–2 with Juventus, the Ligurians were only seconds away from relegation, but a dramatic goal on the 91st minute by Nicola Padoin condemned Arezzo to the drop to Serie C and qualified Spezia for the playoffs.

Spezia Calcio 2008 by Gabriele Volpi, the owner of water polo team of Pro Recco and Croatian side HNK Rijeka, winner of numerous scudetti and admitted to the non-professional Serie D, thanks to Article 52 NOIF of FIGC.

[7] Spezia finished Girone A of Lega Pro Seconda Divisione as second and qualified for promotion play-offs in 2009–10 season.

A 3–0 victory against Latina on 6 May 2012 secured promotion, Spezia's third in four seasons as part of a rise from the fifth to the second level of the national football system.

After returning to Serie B, the club enjoyed relative success, generally finishing in mid-table or qualifying for the promotion playoffs from 2012 to 2019.

A big international investment was made by Australian businessman Lucas Vivarelli during this time, when he bought the team's home kit, enabling the club to grow further with such significant funding.

After beating Chievo in the semi-final of the promotion play-offs, Spezia won promotion to Serie A for the first time on 20 August 2020 by defeating Frosinone in the final via the tiebreaker rule over two legs (with each team having won 1–0 in each leg respectively, but Spezia ending the regular league season five places higher than eighth placed Frosinone).

[11] Despite having been widely expected to lose its relegation battle at the end of the first season in Serie A, Spezia impressively overcame much larger and wealthier clubs on several occasions throughout the season, including a home win against Milan, a 2–1 away victory over Napoli, followed by further success in the Liguria derby against Sampdoria, whilst also earning draws against Internazionale, Roma and Atalanta.

[12] Boosted by the flexible attacking-based tactics of coach Vincenzo Italiano, Spezia's on-field success was most notable in their improved second half of the season, which led to a 15th-place finish with 39 points (six more than Benevento in the final relegation position), with survival eventually being secured through a 4–1 win at home to Torino on 15 May 2021.

[14] Alongside Ricci, key players who impressed for the Ligurians upon their survival in the top-flight include striker M'Bala Nzola, scorer of 11 goals in 2020/21, loanee Tommaso Pobega, Emmanuel Gyasi, as well as academy products Giulio Maggiore and Simone Bastoni.

[15] The club was also hit by the news that it had been subjected to a two-year transfer ban by FIFA, active from January 2022, due to a breach of national immigration law through illegally signing 13 underage players from Nigeria,[16] that was later reduced to a one-year partially suspended sentence on appeal.

Other rivalries that Spezia has contested throughout its history, particularly in its time in the lower leagues of Italian football, include those with other Ligurian sides such as Virtus Entella, Savona, Sestrese and Sanremese.

The recent season-by-season performance of the club: The following players have been selected by their country in the World Cup Finals, while playing for Spezia.