Ronny Deila is a Norwegian former footballer and currently the head coach of New York City FC in Major League Soccer.

As a player, Deila spent the majority of his career at Norwegian soccer side Odds Ballklubb (Odd), as well as enjoying spells at Uraedd, Viking, Stromsgodset, and Sparta Brageroen.

He coached Norwegian fourth-tier side Brodd in 2005 before a highly successful stint in charge of Stromsgodset from 2008 to 2014.

Deila took over at Celtic after his leaving Stromsgodset. He won the Scottish Premiership in 2014/15 and 2015/16, and the League Cup in 2014/15. He stepped down after two seasons and moved to Norweigan side Valerenga.

In January 2020, he was appointed head coach of New York City FC.

Having started his playing career with lower-league Uraedd, Deila joined Odd in 1993 and enjoyed 11 years at the heart of their defence, playing a key role for the side, winning the 2000 Norwegian Football Cup.

In 2004, Deila moved on to Viking, before beginning his coaching career in 2005. That did not mark the end of his playing career. In 2006, he moved to Stromsgodset, where he initially served as a player and assistant coach.

In 2008, he was promoted to head coach and retired from playing professionally, although he did play part-time for lower league Sparta Brageroen from 2009 to 2011.

Deila's first few years in charge of Stromsgodset were challenging as the team continuously fought to survive relegation. However, his attacking brand of football began to bear fruit over time and a key sign of progress was the Norwegian Cup win in 2010.

In 2013, Deila led Stromsgodset to the Tippeligaen title - the club's first in 43 years - and won the Kniksen Award for Coach of the Year.

Deila left Stromsgodset and was appointed Celtic manager in June 2014 on a 12-month rolling contract.

Deila got off to a mixed start at Celtic. Despite occasional incredible performances, he was not universally loved. Former Celtic striker John Hartson described him as "clueless" in October 2014. However, by February 2015, Hartson had reversed his position and praised Deila's Celtic for playing "brilliant football".

Celtic won their first trophy under Deila in March 2015, with Kris Commons and James Forrest scoring in a 2-0 League Cup final win over Dundee United.

On May 2nd 2015, Celtic were crowned Scottish champions with three games to spare due to Aberdeen's loss to Dundee United.

Celtic retained their Scottish Premiership title in 2015/16, but pressure began to mount on Deila due to their performances in other competitions.

After being eliminated from the UEFA Champions League play-offs by Malmo, Celtic crashed out of the UEFA Europa League at the group stage. On 17 April 2016, Celtic lost to fierce rivals Rangers in the Scottish Cup semi-finals at Hampden.

Days later, Deila announced his intention to stand down from his role as manager of Celtic.

Deila left Celtic at the end of the 2015/16 season and moved to Valerenga. He inherited a struggling team and was unable to improve their fortunes. The team finished mid-table in all of the seasons Deila was in charge.

In October 2018, Deila admitted that he was considering his position at the club after a dreadful run of form.

He stepped down as manager after the 2019/20 season, with a win percentage rate of 37.5%.

Deila took over as head coach of New York City FC in January 2020.

He guided them to the first round of the 2020 MLS Cup playoffs, where they lost to Orlando City on penalties after a 1-1 draw.

New York City made the quarter-finals of the MLS Is Back tournament immediately after the COVID-19 pandemic, but they were beaten 3-1 by Portland Timbers.

Deila also guided his side to the CONCACAF Champions League quarter-final, however lost 5-0 on aggregate to Tigres UANL.

Deila is the father of handball players Thale Rushfeldt Deila and Live Rushfeldt Deila.

It is reported that Ronny Deila's net worth is between $1-5million.