Major professional tennis tournaments before the Open Era
Before the advent of the Open era of tennis competitions in April 1968, only amateurs were allowed to compete in established tournaments, including the four Majors. There was no prize money and players were compensated for travel expenses only. However many top tennis players turned professional to play legally for prize money in the years before the open era. They played in separate professional events, mostly on tours involving head-to-head competition, but also in professional tournaments as the biggest events on the pro tour. Professional tournaments, in particular the professional Majors, usually only had a men's draw.
Professional Majors
In addition to the head-to-head tours, there were the annual professional tournaments called Championship tournaments, where the world's top professional male players played. These tournaments held with a certain tradition and longevity. According to Ellsworth Vines, "the Wembley tournament in London..., the U.S. professional championship, and to some extent the tournament in Paris were the major professional tournaments prior to 1968."The oldest of these three Professional Majors, or "Pro Slams", was the U.S. Pro Tennis Championships, played at a variety of different venues and on a variety of different surfaces, between 1927 and 1999. The most prestigious of the three was generally the Wembley Championship. Played between 1934 and 1990, at the Wembley Arena in England, it was unofficially usually considered the world's championship until 1967. The third professional major was the French Pro Championship, played between 1934 and 1968, on the clay-courts of Roland Garros, apart from 1963–1967, when it was played on the indoor wood courts of Stade Coubertin.
Jack Kramer designated the four major professional tournaments for the 1958/1959 seasons as follows; Forest Hills, Kooyong, L.A. Masters, Sydney.
U.S. Pro Tennis Championships
The U.S. Pro Tennis Championship, also known as the US Pro, was an annual tournament, later known as MFS Pro Championships. It was first organized by player Vinnie Richards when promoter C. C. Pyle withdrew interest in the project. It was first played on the Notlek courts located at 119th Street and Riverside Drive, Manhattan. The tournament was held at various locations in several states until 1964, when it moved to the Longwood Cricket Club in Chestnut Hill, Massachusetts.French Pro Championship
The French Pro Championship was first held in 1930, held by the "Association Française des Professeurs de Tennis ", entitled "Championnat International de France Professionnel" in June, 18-22, 1930. From 1930 the French Pro Championship was always played at Paris, on outdoor clay at Roland Garros except from 1963 to 1967 where it was held at Stade Pierre de Coubertin on indoor wood.Wembley Championship
The Wembley Championship, also known as the Wembley Pro, was held at the Wembley Arena, in London. This professional event ran from 1934–1967 and was originally played on a wood surface placed over the top of a drained pool. It was officially known as the "London Indoor Professional Championships" from 1951 through 1967.List of Professional Majors champions
Notes:Other important tournaments
, the US Championships, the French Championships, and the Australian Championships were typically the top events, where amateur players could compete for the title, albeit without prize money. Since the professional circuit was less organized and somewhat less popular than the amateur circuit, the professional events hierarchy changed each year. In 1934 the US Pro was a high-class tournament with all top ranked pro players whereas in 1936 it was a meeting between pro teachers without any leading pro players. A tournament could even be canceled at any time due to poor attendance.Consequently, for a given year a pro tournament was important when it attracted the best pro players and then another year this same tournament could be a second-rank tournament because few or no leading players came. Before the open era in addition to numerous small tournaments and head-to-head tours between the leading professionals, there were some major tournaments which stood out at different periods. Some survived sporadically because of financial collapses while others temporarily rose to the highest levels of competition when other tournaments weren't held. These include:
Bristol Cup: 1920–1932
Sometimes labelled "Professional Championships of France" this tournament was held on the French Riviera at Menton, at Cannes.List of Bristol Cup winners:
Professional Championship of the World: 1927–1928
This event was held in October on Clay courts, at the Queen's Club in London. In 1928 Myers of the Daily Telegraph wrote that "this was the best pro tournament ever held in England."List of Queen's Club Pro winners:
| Year | Champion | Runner-up | Score |
| 1927 |  Dan Maskell | Charles R Read | 6–3, 6–3, 6–4 |
| 1928 |  Robert Ramillon |  Edmund Burke | 6–1, 6–3, 5–7, 6–4 |
World Pro Championship: 1932–1933
The World Pro Championship were held in 1932 and 1933 in Berlin at the Rot-Weiss club, on clay. It had a very large participation. According to Ray Bowers in the History of the Pro Tennis Wars Chapter IV, this tournament at the time was regarded as the most prestigious professional tournament in the world.List of World Pro winners:
| Year | Champion | Runner-up |
| 1932 | Martin Plaa |  Bill Tilden |
| 1933 |  Hans Nüsslein | Bill Tilden |
Bonnardel Cup: 1935–1937
This was a team tournament created by Bill Tilden and modeled on the Davis Cup format. In 1935, early rounds in France were hoped to be played at Roland Garros, but the French Tennis Association would not allow the event to be played at the stadium.| Year | Champions |
| 1935 | France |
| 1936 | United States |
| 1937 | France |
International Pro Championship of Britain: 1935–1939
The International Pro Championship of Britain was a professional tennis tournament held at Victoria Park in Southport between 1935 and 1939. It was open to professional players only, amateurs were not allowed to compete. The tournament was held on outdoor En-tout-cas, "all-weather" artificial clay.List of International Pro Championship of Britain winners:
;Singles
| Year | Champion | Runner-up | Score |
| 1935 |  Ellsworth Vines | Bill Tilden | 6–1, 6–8, 4–6, 6–2, 6–2 |
| 1936 | Hans Nüsslein | Henri Cochet | ' |
| 1937 | Hans Nüsslein | Robert Ramillon | 6–4, 6–3, 2–6, 6–4 |
| 1938 | Hans Nüsslein | Bill Tilden | ' |
| 1939 | Hans Nüsslein | Bill Tilden | 6–2, 7–5, 6–4 |
;Doubles
| Year | Champions | Runners-up | Score |
| 1935 | Bill Tilden Ellsworth Vines | Martin Plaa Robert Ramillon | 7–5, 6–8, 5–7, 6–1, 6–3 |
| 1936 | Henri Cochet Robert Ramillon | Lester Stoefen Bill Tilden | ' |
| 1937 | Lester Stoefen Bill Tilden | Martin Plaa Robert Ramillon | 8–6, 17–15, 8–6 |
| 1939 | Don Budge Ellsworth Vines''' | Lester Stoefen Bill Tilden | 6–2, 7–9, 7–5, 8–6 |
U.S Pro Hard Courts: 1945–1946
In LA; the only significant pro tournament of the last year of World War II.| Year | Champion |
| 1945 | Bobby Riggs |
| 1946 | Bobby Riggs |
Philadelphia Indoor Pro: 1950–1952
| Year | Champion |
| 1950 | Pancho Gonzales |
| 1951 | Jack Kramer |
| 1952 | Pancho Gonzales |
Australian Pro: 1954–1966
This had multiple venues from the east and west coasts of Australia and was not played in 1955, 1956, 1961 and 1963.List of Australian Pro winners:
| Year | Champion | Runner-up | Score |
| 1966 |  Rod Laver | Ken Rosewall | |
| 1966 | Ken Rosewall | Pierre Barthes | |
| 1965 | Rod Laver | Pancho Gonzales | |
| 1965 | Rod Laver | Ken Rosewall | |
| 1964 | Rod Laver | Ken Rosewall | |
| 1962 | Ken Rosewall |  Andrés Gimeno | |
| 1960 | Ken Rosewall | Lew Hoad | |
| 1959 | Lew Hoad | Ken Rosewall | |
| 1958 | Frank Sedgman | Tony Trabert | |
| 1957 | Pancho Segura | Frank Sedgman | |
| 1954 | Frank Sedgman | Pancho Segura | 5–7, 6–3, 6–4 |
Tournament of Champions: 1957–1959
The Tournament of Champions was a professional tennis tournament between 1957 and 1959. The tournament was held on the grass-courts of Forest Hills, New York, between 1957 and 1959, and an Australian version of the Tournament of Champions was held on grass at White City, Sydney in 1957 and 1959, and at Kooyong Stadium in Melbourne in 1958. The 1957 and 1958 Forest Hills tournaments had a round robin format, while the 1959 Forest Hills was an elimination tournament with 10 players. The Sydney version was an elimination event, while the 1958 Kooyong event was a round robin format.The Forest Hills Tournament of Champions was broadcast nationally in the U.S.A. on the CBS television network, the only professional tennis tournament in the U.S.A. to achieve this status.
The 1958 Kooyong Tournament of Champions was the richest tournament of the era, with a prize money of 10,000 Australian pounds.
In 1968, the tournament was picked up again for a one off tournament during the open era and called Jack Kramer's Tournament of Champions held at Wembley Arena.
List of Tournament of Champions winners:
;Forest Hills
| Year | Champion | Runner-up | Score |
| 1957 | Pancho Gonzales | Frank Sedgman | ' |
| 1958 | Pancho Gonzales | Ken Rosewall | ' |
| 1959 | Lew Hoad | Pancho Gonzales | 6–1, 5–7, 6–2, 6–1 |
;Sydney White City and Melbourne Kooyong
| Year | Champion | Runner-up | Score |
| 1957 | Pancho Segura | Frank Sedgman | 7–5, 6–0, 6–4 |
| 1958 | Lew Hoad | Frank Sedgman | |
| 1959 | Pancho Gonzales | Lew Hoad | 11–9, 6–1, 6–1 |
;London
| Year | Champion | Runner-up | Score |
| 1968 | Ken Rosewall | John Newcombe | 6–4, 4–6, 7–5, 6–4 |
Masters Pro: 1956–1967
Round Robin in Los Angeles, held from 1956 to 1960, and again in 1964, 1965, and 1967.Masters Pro winners:
| Year | Champion | Runner-up | Score |
| 1956 | Pancho Gonzales | Frank Sedgman | ' |
| 1957 | Pancho Gonzales | Frank Sedgman | ' |
| 1958 | Pancho Segura | Pancho Gonzales | ' |
| 1959 | Pancho Gonzales | Lew Hoad | ' |
| 1960 | Ken Rosewall | ||
| 1964 | Ken Rosewall | Frank Sedgman | 6–2, 6–4 |
| 1965 | Rod Laver | Pancho Gonzales | 3–6, 6–3, 7–5 |
| 1967 | Ken Rosewall |
Kramer Cup: 1961–1963
A team format tournament.| Year | Champions |
| 1961 | Australia |
| 1962 | Australia |
| 1963 | Australia |
Madison Square Garden Pro: 1966–1967
Madison Square Garden Pro winners:| Year | Champion | Runner-up | Score |
| 1954 | Pancho Gonzales |  Pancho Segura | 7–9, 6–4, 6–4 |
| 1966 | Ken Rosewall | Rod Laver | 6–3, 6–3 |
| 1967 | Rod Laver | Ken Rosewall | 6–4, 6–4 |
| 1968 | Tony Roche | Pancho Gonzales | 6–3, 6–4 |
| 1969 | Rod Laver | Roy Emerson | 6–2, 4–6, 6–1 |
Forest Hills Pro: 1966
The Forest Hills Pro was held in June 1966 on the grass courts of the West Side Tennis Club using the VASSS Scoring SystemForest Hills Pro winner:
Wimbledon Pro: 1967
The Wimbledon World Professional Championship, also known as the Wimbledon Pro, was held in August 1967. The tournament was sponsored and broadcast by the BBC to mark the invention of colour television. It was first time that professional tennis players played at Wimbledon.Wimbledon Pro winner:
| Year | Champion | Runner-up | Score |
| 1967 | Rod Laver | Ken Rosewall | 6–2, 6–2, 12–10 |