Mercedes Formula One driver Hamilton, who is bidding to win his fourth World Championship this year, has a £131m fortune and has seen his wealth increase by £25m in the last 12 months.
Ibrahimovic, United's 35-year-old Swedish striker, leapfrogged team-mate Wayne Rooney to become the richest footballer on the list after he joined the English side in July last year.
The imposing forward has a wealth of £110m after more than a decade playing for Europe's elite clubs including Paris St Germain, AC Milan, Barcelona, Juventus and Inter Milan and a lucrative long-term endorsement deal with Nike.
Formula One's Jenson Button and golfer Rory McIlroy make up the top five with wealth of £86m and £82m respectively.
McIlroy's fortune rose by £26m in the last 12 months, the biggest rise on the list, while Button's personal fortune grew by £9m even though he handed over his McLaren seat at the end of last season.
Football is the best-represented sport in the top 10, with five of the wealthiest sports people either players or managers.
Rooney (£93m, up £11m) is third, while Manchester United manager Jose Mourinho is in seventh place (£61m) and Manchester City boss Pep Guardiola equal ninth (£50m).
Wales and Real Madrid striker Gareth Bale has seen his wealth rise by £20m in the last year to a total of £54m, to place him eighth in the top 10.
Sir Andy Murray is now worth £77m, making him the sixth-richest sportsman. The world number one in men's tennis earned nearly £13m on court and plenty more off it to carry him to the total, the same number as that borne by his management company after he won his first Wimbledon 77 years after the last Briton to do so, Fred Perry.
Los Angeles Lakers basketball player Luol Deng completes the top 10 in joint ninth place with Guardiola (£50m).
Deng is Sudanese-British and came to London aged eight after fleeing civil war in his home country. He moved to the United States as a teenager and has played for the Chicago Bulls, the Cleveland Cavaliers and the Miami Heat before switching to the Lakers.
None of the top 10 richest sports stars saw their wealth decline this year, with the cumulative rise standing at £129m.