1970 Pacific Southwest Open – Men's singles

The 1970 Pacific Southwest Open – Men's singles was an event of the 1970 Pacific Southwest Open tennis tournament and was played on outdoor hard courts at the Los Angeles Tennis Center in Los Angeles, California, in the United States between September 21 and September 27, 1970. Pancho Gonzales was the defending Pacific Southwest Open champion but was defeated in the quarterfinals. First-seeded Rod Laver won the title by defeating second-seeded John Newcombe 4–6, 6–4, 7–6(7–5) in the final.

Seeds
• 🇦🇺 Rod Laver (champion)

• 🇦🇺 John Newcombe (final)

• 🇦🇺 Tony Roche (third round)

• 🇦🇺 Roy Emerson (first round)

• 🇺🇸 Pancho Gonzales (quarterfinals)

• 🇺🇸 Cliff Richey (second round)

• 🇺🇸 Arthur Ashe (semifinals)

• 🇪🇸 Andrés Gimeno (third round)

• 🇺🇸 Dennis Ralston (second round)

• 🇬🇧 Roger Taylor (third round)

• Tom Okker (second round)

• 🇺🇸 Stan Smith (quarterfinals)

• 🇦🇺 Fred Stolle (third round)

• 🇺🇸 Clark Graebner (quarterfinals)

• Nikola Pilić (third round)

• 🇺🇸 Marty Riessen (quarterfinals)