Born and raised in Caldwell, Idaho, Englehorn was introduced to golf by Shirley Spork, one of the thirteen founders of the LPGA, and also studied with Johnny Revolta, an 18-time PGA Tour winner and the PGA Championship victor in 1935.
She won many amateur and open events, including the McCall Open in 1957 and 1958, the Idaho Open from 1957 to 1959 and the Pacific Northwest Amateur in 1958. She also won the Oregon Open in 1959 and was the youngest player ever to receive the Dorothy Pease Trophy (Trans-Miss) at the age of 15.
After graduation from Caldwell High School in 1958, Englehorn turned pro at age 18 in 1959 and joined the LPGA Tour. She was sponsored by the Athletic Round Table of Spokane from 1960 through 1962. Despite a career-threatening equestrian accident in Georgia in March 1960, Englehorn recovered and won her first tournament at age 21 in July 1962 at the Women's Eastern Open in Sutton, Massachusetts. She won a total of 11 events on the LPGA Tour, including one major championship, the LPGA Championship in 1970 in a playoff over Kathy Whitworth, her third victory at Sutton.
Englehorn led the tour that season in wins with four. Five years earlier in 1965, she suffered injuries in an automobile accident and missed much of the season. Englehorn was awarded the Ben Hogan Award in early 1968 by the Golf Writers Association of America in honor of her successful comeback from injuries. She had surgery on her ankle in 1971 and 1973 and in each case returned to compete. She later became a golf instructor, and won the LPGA Teacher of the Year Award in 1978. Her last LPGA appearance was in 1979.