Nottingham U21

19th century

From 2019 to 2023, Nottingham Forest claimed to be the oldest remaining club in the English Football League. In 2019, when Notts County were relegated from the league, Stoke City claimed to be the oldest remaining club, but football historian Mark Metcalf stated that Stoke was formed in 1868, rather than the 1863 date on the club's badge, and therefore Forest was the oldest club. The EFL also stated that Nottingham Forest was the oldest.

In 1865 a group of shinty players met at the Clinton Arms (now renamed The Playwright) at the junction of Nottingham's Shakespeare Street and North Sherwood Street. J. S. Scrimshaw's proposal to play association football instead was agreed and Nottingham Forest Football Club was formed. It was agreed at the same meeting that the club would purchase twelve tasselled caps coloured 'Garibaldi Red' (named after the leader of the Italian 'Redshirts' fighters). Thus the club's official colours were established. Matches were originally played at Forest Racecourse, historically part of Sherwood Forest and the presumed source of the word 'Forest' in the team's name.

Forest's first ever official game was played against Notts County taking place on 22 March 1866. On 23 April 1870, when the team played their first game in league play, the steward of the club was John Lymberry and William Henry Revis scored the first goal. On that day, Revis also won the prize for kicking a football furthest with a kick of 161 feet 8 inches.

In their early years Nottingham Forest were a multi-sports club. As well as their roots in bandy and shinty, Forest's baseball club were British champions in 1899. Forest's charitable approach helped clubs like Liverpool, Arsenal and Brighton & Hove Albion to form. In 1886, Forest donated a set of football kits to help Arsenal establish themselves – the North London team still wear red. Forest also donated shirts to Everton and helped secure a site to play on for Brighton.

In 1878–79 season, Nottingham Forest entered into the FA Cup for the first time. Forest beat Notts County 3–1 in the first round at Beeston Cricket Ground before eventually losing 2–1 to Old Etonians in the semi-final.

Nottingham Forest's application was rejected to join the Football League at its formation in 1888. Forest instead joined the Football Alliance in 1889.

They won the competition in 1892 before then entering the Football League. That season they reached and lost in an FA Cup semi-final for the fourth time to date. This time it was to West Bromwich Albion after a replay.

Nottingham Forest's first FA Cup semi-final win was at the fifth attempt, the 1897–98 FA Cup 2–0 replay win against Southampton. The first game was drawn 1–1. Derby County beat Nottingham Forest 5–0 five days before the final. Six of the cup final side were rested in that league game. In that 1898 FA Cup final at Crystal Palace before 62,000 fans, Willie Wragg passed a 19th minute free kick to Arthur Capes. Capes shot through the defensive wall to score. Derby equalised with a free kick headed home by Steve Bloomer off the underside of the cross bar after 31 minutes. In the 42nd minute Jack Fryer was unable to hold a Charlie Richards shot giving Capes a tap in for his second goal. Wragg's injury meant Forest had to change their line up with Capes dropping back to midfield. In the 86th minute John Boag headed away a corner by Nottingham Forest. John McPherson moved in to collect shooting low into the goal to win 3–1.

First half of 20th century

Forest lost FA Cup semi-finals in 1900 and 1902. They finished fourth in the 1900–01 Football League followed with fifth place the season after. The club then started to slide down the table. Forest were relegated for the first time in 1905–06. Grenville Morris had his first of five seasons as the club's highest scorer en route to becoming the all-time club highest goalscorer with 213 goals.

Promotion as champions was immediate in 1906–07. The club was relegated a second time to the Second Division in 1911, and had to seek re-election in 1914 after finishing bottom of that tier; as the First World War approached it was in serious financial trouble. The outbreak of the War, along with the benevolence of the committee members, prevented the club going under.

In 1919, the Football League First Division was to be expanded from twenty clubs to twenty-two in time for the 1919–20 Football League: Forest was one of eight clubs to campaign for entry, but received only three votes. Arsenal and Chelsea gained the two additional top tier slots.

In a turnaround from the first six seasons struggling back in the Second Division, Forest were promoted as champions in 1921–22. They survived each of the first two seasons back in the top flight by one position. In the third season after promotion they were relegated as the division's bottom club in 1924–25. Billy Walker was appointed manager in 1939. Forest remained in the second tier until relegation in 1949 to the Football League Third Division South.

Re-emergence then decline (1950–1974)

Forest were quickly promoted two years later as Third Division South champions, having scored a record 110 goals in the 1950–51 season. They regained First Division status in 1957.