Leeds Prison is the most overcrowded in England, according to a report by the Howard League for Penal Reform.
The facility was built to hold nearly 700 prisoners, but the league's report found the Category B site had more than 1,200 inmates at the end of January.
The charity found that 64 of the 75 Category B and Category C men's prisons in England and Wales had more inmates than they were designed to hold.
Leicester had 361 prisoners instead of 214 and Wandsworth was 663 over.
The league analysed Ministry of Justice (MoJ) data obtained under the Freedom of Information Act.
The prison population rose from 83,062 to 83,680, across the period looked at. Overcrowding was also particularly bad in Exeter, Preston, Durham and Doncaster prisons, the league said.
Population levels 'safe'
Prisoners have been "doubled-up" or "trebled-up" - two or three prisoners in a cell designed for one - increasingly often, according to the data.
The league said that on a typical day, almost 19,000 prisoners were doubled-up and about 800 were trebled-up.
England's most overcrowded prisons
- Leeds: Designed to accommodate 669 but was holding 1,218 at the end of January 2015
- Wandsworth: Designed to accommodate 943, but holding 1,606
- Leicester: Designed to accommodate 214, but holding 361
- Exeter: Designed to accommodate 318, but holding 530
- Preston: Designed to accommodate 433, but holding 682
Source: The Howard League for Penal Reform
Chief Executive Frances Crook said: "Far too many people are being sent into already overcrowded jails and the need to stem the flow is now urgent.
"Government must get a grip on a prison system in crisis that is feeding the crime problem and creating more victims."
Prisons minister Andrew Selous said: "We always have enough space within our prisons to accommodate all offenders and will never be in a position where we can't imprison those sentenced by the courts.
"All prisons have safe population levels and published statistics show that crowding is at its lowest levels since 2007/08."