Hannant spent his youth at the Academy at Norwich City before being released at the age of 14, at which point he joined the Cambridge United youth-team. Released by Cambridge at the age of 18, he took up a football scholarship at Northumbria University, and would go on to graduate with a 2:1 degree in Sport & Exercise Science in 2016. During this time he also played in the Eastern Counties League and Isthmian League for Dereham Town and in the Northern League for Team Northumbria. He was an important part of the "Magpies" side that finished the 2012–13 season as champions of the Eastern Counties League Premier Division.
Gateshead
He spent the summer of 2016 on trial at Gateshead before agreeing to join the club on non-contract terms. He went on to join Northern League Division One club South Shields on a dual registration deal. He scored on his debut for the "Mariners" in a 5–0 home win over Jarrow Roofing Boldon Community Association on 27 September. He played a total of four games for South Shields. He made his National League debut for the "Tynesiders" on 22 October, in a 2–0 win at Maidstone United. He scored his first goal for the "Heed" on New Year's Eve, in a 4–1 victory over Barrow at the Gateshead International Stadium, where he was also named as Man of the Match. He was signed to a contract at Gateshead in March 2017, which would keep him tied to the club in summer 2018. He ended the 2016–17 season with two goals in 21 appearances, and scored three goals in 23 games in the first half of the 2017–18 campaign. Speaking in January 2018, manager Steve Watson said that "Hannant has been one of our best players this season".
Port Vale
On 18 January 2018, Hannant signed an 18-month contract with EFL League Two side Port Vale after being signed for an undisclosed fee – reported to be a low five-figure sum – by Neil Aspin, his former manager at Gateshead. Despite being a newcomer to the English Football League, he was described as "a rare positive for the Valiants in a difficult start to 2018", and credited his good start to his career to the support of fellow midfielders Michael Tonge, Antony Kay and Danny Pugh. On 17 March, he scored his first goal in the Football League with curling effort from outside the box in a 2–2 draw with Stevenage at Vale Park; he went on to say that "I was a bit speechless when it went in". He began the 2018–19 season in good form on the left-side of midfield, scoring two goals in the opening five games, including a brilliant curling free-kick away at Carlisle United. This led to reports that he was being monitored by EFL Championship club Bolton Wanderers. However despite making 50 appearances during the campaign, manager John Askey confirmed that he would not be offering Hannant a new contract on 16 May.
Cambridge United
On 28 May 2019, Hannant returned to Cambridge United to sign on a two-year deal with an option for a further year. Manager Colin Calderwood said that "Luke has good experience in senior football and caught my eye against us at the Abbey". He picked up an ankle injury in February 2020 and was sidelined for six weeks.
Style of play
Hannant is a versatile two-footed attacking midfielder, who is able to play in central midfield or as a winger. Port Vale teammate Tom Pope described him as a player with "good energy, is positive, doesn’t mind a tackle, is decent in the air and can play as well".
Career statistics
Honours
Dereham Town
Eastern Counties League Premier Division champion: 2012–13
