25: New York City FC (MLS)
Owned by Sheikh Mansour's City Football Group, the same holding company that owns Manchester City, New York City was only founded in 2015.
In the three years that have followed, New York City has gone from strength to strength as Forbes recently valued the club at €227.25 million — the fourth highest valuation in the whole of the MLS.
The club has few fixed assets as it ground shares the Yankee Stadium, but the backing of City Football Group means the potential for future investment is huge.
24: Seattle Sounders (MLS)
Last year, Forbes listed the Sounders as one of the most profitable football franchises in the MLS, second only to the LA Galaxy.
The club has on-field success thanks to back-to-back MLS Cup appearances, has a huge fan-base that regularly sees home attendances soar above 40,000, and is backed by four individual investors willing to bring key talent like Clint Dempsey to the club.
23: New York Red Bulls (MLS)
Red Bull's ownership of New York Red Bulls revolutionised the club.
It moved its training facilities to a 73 acre property in New Jersey worth €5 million in 2013 and has a modern 25,000-seater ground nearby.
22: Shaktar Donetsk (Ukrainian Premier League)
Political instablity in Ukraine forced FC Shakthtar Donetsk out of Lviv and into Karviv, 150 miles to the north of Donetsk.
Despite this, Shakhtar continues to win championships, cups, and other minor titles thanks to a strong squad filled mainly with local talent and Brazilian imports.
The club is owned by Rinat Akhmetov, one of the wealthiest billionaires in Ukraine.
next slide will load in 15 secondsSkip AdSkip Ad21: Bayer Leverkusen (Bundesliga)
Owned by multinational pharmaceutical giant Bayer AG, Bayer Leverkusen is seen as a stable club because of a roster with strong players, the BayArena, a 30,000-seater ground renovated in 2009, and low debt levels.
Bayer Leverkusen's association with Bayer AG stretches back to its inception in 1904.
20: Leicester City (Premier League)
Leicester City's fairytale march toward the Premier League title in 2016 and the subsequent foray in the Champions League gave a huge boost to the club's financial health.
Leicester City owner King Power Group, led by Vichai Srivaddhanaprabha, means the Foxes benefit from substantial investment.
19: AS Monaco (Ligue 1)
AS Monaco is majority owned by Russian billionaire Dmitry Rybolovlev.
Since Rybolovlev acquired his 66.6% stake in 2011, the club won Ligue 2 in 2012 and Ligue 1 in 2017.
There will be a lot of money in the bank coming in this year as Paris Saint-Germain will likely make the loan purchase of Kylian Mbappé a permanent one in a trade that could see Monaco make €180 million.
One obvious area of improvement is Stade Louis II, which only has a matchday capacity of 18,500 seats.
18: Olympique Lyon (Ligue 1)
Olympique Lyon is co-owned by French businessman Jean-Michel Aulas and minority partner IDG Capital Partners, a financial services firm.
The club's home ground, the Groupama Stadium, has a capacity of 60,000 seats.
Additionally, the club has a number of top playing assets including captain Nabil Fekir, who is worth €55.7 million according to CIES Football Observatory.
17: Borussia Dortmund (Bundesliga)
Borussia Dortmund is a financially secure club in Germany.
Though it fails to match Bayern Munich's might, it benefits from low debt levels, the Signal Iduna Park — which is the biggest stadium in Germany —, and a talented squad.
19-year-old midfielder Christian Pulisic (pictured above, number 22) is worth €75.2 million according to CIES Football Observatory.
next slide will load in 15 secondsSkip AdSkip Ad16: Liverpool FC (Premier League)
John W. Henry's Fenway Sports Group bought Liverpool FC in 2010, and it's widely regarded to be a strong global brand.
During the Fenway Sports Group's tenure, Liverpool has only won one minor title — the League Cup.
However, it has benefited from a large investment. In the last year alone the club has twice broken its own transfer fee record.
In-form attacking midfielder Mohamed Salah, bought for €50 million in 2017, is one of the Premier League's top scorers this season.
15: Atletico Madrid (La Liga)
The recent investment of Wanda Group, the world's largest property developer, has positively impacted Atletico Madrid.
The club's most treasured athlete is striker Antoine Griezmann who has a market value of €150.6 million according to CIES Football Observatory.
In terms of fixed assets, Atlético moved into its new ground — the 67,000 seater Wanda Metropolitano — in 2017.
14: LA Galaxy (MLS)
Soccerex says the inclusion of LA Galaxy at 14th is "largely due to solid business models, high-value assets and strong investment."
The club has virtually non-existent net debt levels and is owned by entertainment juggernaut AEG.
13: FC Barcelona (La Liga)
An economic power-ranking of football clubs would usually see FC Barcelona placed higher, but Soccerex says "member ownership structures and the lack of potential owner investment" at Barça means it scores poorly here.
Barcelona's home ground Camp Nou pushes a 100,000 seater capacity and is the largest stadium in Europe.
Playing assets like Lionel Messi also ensure the club's squad is one of the most valuable in the world.
12: RB Leipzig (Bundesliga)
Austria conglomerate Red Bull, known for its energy drink of the same name, founded the club in 2009. In that time, the club has won four promotions and is currently campaigning in Germany's top flight, the Bundesliga.
In its debut season, average home league attendances were little more than 2,000 per game. Now, Leipzig expects 41,500 fans at every home game. The level of growth in just eight years is huge.
21-year-old striker Timo Werner is one of the club's best players and is worth €92.5 million according to CIES Football Observatory.
next slide will load in 15 secondsSkip AdSkip Ad11: Zenit St Petersburg (Russian Premier League)
Zenit St Petersburg's owner is gas giant Gazprom, one of the biggest companies in Russia.
The Gazprom era has lasted 12 years and in that time the club won the Russian Premier League four times, the Russian Cup twice, and the UEFA Cup in 2008.
Gazprom has not been averse to investing in Zenit and has backed manager Roberto Mancini in the transfer markets.
10: Bayern Munich (Bundesliga)
The German powerhouse is one of the most stable football clubs on the planet, yet has no wealth investor like its Premier League rivals.
Bayern Munich has elite training facilities, a state of the art stadium in the Allianz Arena, and a big squad of in-form and valuable players like striker Robert Lewandowski, midfielder Arturo Vidal, and defender Joshua Kimmich.
9: Chelsea (Premier League)
Roman Abramovich is one of the wealthiest billionaire owners in England according to this Business Insider report, yet this counts for little in the Soccerex report as "the owner's invesment is [seen as] a loan."
Though there is no timescale to pay the loan back, the heavy investment means Chelsea has the most net debt out of all clubs on Soccerex's list. If Chelsea's debt to Abramovich is written off "as sponsorship" then "the Blues would rank higher."
The club's top talent, Eden Hazard, is worth €120.7 million according to CIES Football Observatory.
8: Juventus (Serie A)
Young and in-form players like Paulo Dybala and Miralem Pjanic prop up Juve's squad value. Dybala alone is worth €170.6 million according to CIES Football Observatory.
The club is owned by the Agnelli family, who notably control Italy's biggest manufacturer — FIAT — through its holding company EXOR N.V.
The potential for investment in Juventus is big.
7: Manchester United (Premier League)
Manchester United is one of the most famous football clubs on the planet, however, it does not score highly on Soccerex's list as it has the highest debt level of any side in the top 25.
The club is a major player in the transfer market, as its signings of Paul Pogba and Romelu Lukaku in successive summers demonstrates.
next slide will load in 15 secondsSkip AdSkip Ad6: Real Madrid (La Liga)
Spain's biggest clubs traditionally dominate football rich lists. But Soccerex says Real Madrid, like FC Barcelona, is hampered by "membership ownership structures and the lack of potential owner investment."
One of the reasons Real is higher than Barça is because the Madrid club "should be capitalised via the stock markets."
Real has many star players but its biggest name — Cristiano Ronaldo — has seen his transfer value dwindle in recent years thanks, in part, to age.
5: Tottenham Hotspur (Premier League)
Tottenham Hotspur's playing assets are huge thanks to a squad of young and in-form footballers.
The most valuable, striker Harry Kane, is worth €183.7 million according to CIES Football Observatory.
The club is also in the midst of a stadium move which will significantly bolster its matchday income.
4: Guangzhou Evergrande (Chinese Super League)
The growth of China as a football powerbase is underlined by Guangzhou Evergrande's inclusion.
The club is owned by Evergrande and Alibaba Group, two companies with a lot of financial clout. The potential level of investment in the future is huge.
Evergrande has won seven Chinese Super League championship titles in a row.
3: Paris Saint-Germain (Ligue 1)
Qatar Sports Investments and Paris Saint-Germain club president Nasser Al-Khelaifi have revolutionised PSG.
The club shocked the football industry last summer by obliterating the transfer fee record when it signed Neymar in a €220 million deal. It also bought Kylian Mbappé which could cost the club as much as €180 million.
If PSG wants to become the biggest financial powerhouse in football, it will likely have to expand its home ground — the Parc des Princes, a stadium that is small compared to its rivals.
2: Arsenal (Premier League)
Soccerex says Arsenal has a sound business model, deserving of second place in its list.
"This position of financial strength means Arsenal could invest significantly should the hierarchy at the club choose to change its business strategy."
However, the club's playing assets may dwindle in 2018 as star players Mesut özil and Alexis Sánchez will both likely leave Arsenal as their contracts expire in the summer.
Manager Arsène Wenger will hope to either negotiate new deals for özil and Sánchez, or replace them with equal talent in the transfer markets.
next slide will load in 15 secondsSkip AdSkip Ad1: Manchester City (Premier League)
Runaway Premier League leader Manchester City is backed by the wealthiest billionaire football owners in England, according to a recent Business Insider study.
Sheikh Mansour, owner of Manchester City and its parent company the City Football Group, has eliminated net debt thanks to an incredible level of investment since 2008.
"Sheikh Mansour has injected over €650 million into the playing squad and infrastructure and the club’s financial power has been further boosted by huge Premier League broadcast deals," Soccerex says.
Additionally, the club's roster has many valuable footballers like Kevin de Bruyne and Raheem Sterling (pictured above).