Bertha is a female Germanic name, from Old High German berhta meaning "bright one". It was usually a short form of Anglo Saxon names Beorhtgifu meaning "bright gift" or Beorhtwynn meaning "bright joy".

The name occurs as a theonym, surviving as Berchta, a figure in Alpine folklore connected to the Wild Hunt, probably an epithet of *Frijjō in origin.

Bertha appears as a Frankish given name from as early as the 6th century. The monothematic Bertha as a given name may, however, not originate with the theonym but rather as a short form of dithematic given names including the "bright" element. This is notably the case with the mother of Charlemagne, Bertrada (properly berht-rada "bright counsel") called "Bertha Broadfoot." Carolingian uses of the name Bertha, as in the case of Bertha, daughter of Charlemagne and Bertha, daughter of Lothair II, are in this tradition.

In modern times, the name is associated with an unusually large example of a class of objects. Many large machines are nicknamed Bertha for the World War I howitzer known as Big Bertha.

Women named Bertha include:

• Saint Bertha of Kent (539 – c. 612), Queen of Kent
• Saint Bertha of Val d'Or (d. c. 690), abbess
• Saint Bertha of Artois (mid-7th century – 4 July 725), abbess, daughter of Count Rigobert and Ursana
• Bertrada of Laon (also called Bertha with the big feet) (720–783), Frankish queen
• Saint Bertha of Bingen (fl. c. 757), mother of Saint Rupert of Bingen
• Bertha, daughter of Charlemagne (c. 780 – after 11 March 824)
• Bertha, daughter of Lothair II (863–925)
• Blessed Bertha de Bardi, Florence; (died 24 March 1163)
• Bertha, Duchess of Brittany (c. 1114 – 1156)
• Bertha of Burgundy (952, 964 or 967 – 1010, 16 January 1016, or 1035), queen of France
• Bertha of Hereford (born c. 1130), heiress
• Bertha of Holland (c. 1055 – 1093), queen of France
• Bertha of Putelendorf (died 1190), Saxon noble
• Bertha of Savoy (1051–1087)
• Bertha of Sulzbach (1110–1159), Byzantine empress
• Bertha of Swabia (c. 907 – 966), queen of Burgundy
• Bertha of Val d'Or (died c. 690), a Christian saint
• Bertha Benz (1849–1944), wife of automobile inventor Karl Benz and the first person in history to drive an automobile over long distance.
• Bertha Southey Brammall (1878–1957), Australian writer
• Bertha Brainard (1890–1946), pioneering television executive
• Bertha Coombs (born 1961), reporter
• Bertha Díaz (born 1936), Cuban track and field athlete
• Bertha Fowler (1866-1952), American educator, preacher, deaconess
• Bertha Gifford (1871-1951), American serial killer
• Bertha Lund Glaeser (1862-1939), American physician
• Bertha Gxowa (1934-2010), South African anti-apartheid activist, trade unionist, and women's rights activist
• Bertha Hart, American mathematician
• Bertha "Chippie" Hill (1905–1950), American blues and vaudeville singer and dancer
• Bertha von Hillern (born 1857), American athlete and painter
• Bertha Hosang Mah (1896 – 1959), Canadian student
• Bertha Kalich (1874–1939), Jewish actress
• Bertha Krupp (1886–1957), sole proprietor of the Krupp industrial empire from 1902 to 1943
• Bertha Knight Landes (1868–1943), first female mayor of a major American city (Seattle, Washington)
• Bertha Lewis (1887–1931), English opera singer and actress
• Bertha Mahony (1882–1969), publisher of children's literature
• Bertha Palmer (1849–1918), American businesswoman, socialite, and philanthropist
• Bertha Pappenheim (1859–1936), Austrian-Jewish feminist and social pioneer
• Bertha Lee Pate (1903–1975), American blues vocalist
• Bertha Quinn (1873–1951), British suffragette and socialist, recipient of Papal Medal
• Bertha Ronge (1818–1863), Anglo-German kindergarten activist
• Bertha Runkle (1879–1958), American novelist and playwright
• Bertha Sánchez (born 1978), Colombian long-distance runner
• Bertha Schrader (1845-1920), German painter, lithographer, and woodblock print-maker
• Bertha von Suttner (1843–1914), Austrian novelist and pacifist
• Bertha Swirles (1903–1999), English physicist and applied mathematician
• Bertha Tammelin, (1836–1915), Swedish musician, composer and singer
• Bertha Teague (1906–1991), Hall of Fame basketball coach
• Bertha Townsend (1869–1909), American tennis player
• Bertha L. Turner (1867–1938), American caterer, cookbook author, and community leader
• Bertha Valerius (1824–1895), Swedish photographer
• Bertha Yerex Whitman (1892–1984), American architect
• Bertha Wehnert-Beckmann (1815–1901), German photographer
• Bertha Wilson (1923–2007), first female Puisne Justice of the Supreme Court of Canada
• Bertha M. Wilson (1874–1936), American dramatist, critic, actress
• Bertha Zück (1797–1868), German-Swedish royal treasurer