U.S. suffragist and political activist Susan B. Anthony, 1820–1906
Susan, a name most popular from the 1940s–1960s, traces its etymology back to a rather unexpected source—Ancient Egypt. This is one Indo–European name that didn’t originate among the Vikings, Anglo–Saxons, Normans, Goths, Romans, or Greeks.
Sšn means “lotus” in Egyptian, and later morphed into the Ancient Hebrew word shoshan, “lily.” In Modern Hebrew, shoshan means “rose.” It gave rise to the name Shoshanah, and then was adopted by the Greeks as Sousanna.
Over time, it appeared in many European languages in various forms. In the Medieval Anglophone world, Susannah was sometimes used in honour of a woman falsely accused of adultery in the Book of Daniel, and another Biblical woman who ministers to Jesus. Only after the Protestant Reformation did it become more common, in the form of Susan.
French painter Suzanne Valadon (1865–1938) with her son Maurice
Susan was #80 when the U.S. began keeping name records in 1880, and left the Top 100 in 1885. It briefly returned in 1887, then dropped out again and gradually sank in popularity. During the 1930s, it slowly made its way back up the chart, and re-entered the Top 100 in 1937 at #97.
In 1945, it was #10, and entered the Top 5 in 1948. Apart from 1951 and 1966, when it was #6, Susan was in the Top 5 until 1968. Its all-time highest rank was #2, from 1957–60. In 1972, it fell off the Top 20, and left the Top 100 in 1985.
Susan’s last year on the Top 1000 was 2017, when it was #957.
Austrian-born painter Soshana Afroyim (née Susanne Schüller),
1927–2015
Other forms of the name include:
1. Suzanne is French, Dutch, and English.
2. Susanna is English, Dutch, Russian, Ukrainian, Italian, Catalan, Swedish, Estonian, and Finnish. The alternate form Súsanna is Icelandic, Faroese, and Irish; Susánna and Susánná are Sami.
3. Susannah is English.
4. Susana is Spanish and Portuguese.
5. Suzana is Serbian, Slovenian, Macedonian, Brazilian–Portuguese, Romanian, and Croatian.
6. Susanne is German and Scandinavian.
7. Syuzanna is old-fashioned Russian.
8. Suzanna is English.
9. Shoshana, or Shoshanah, is Hebrew.
10. Sawsan is Arabic.
Hungarian Princess Zsuzsanna Lorántffy (1602–1660), who founded and sponsored several schools, including schools offering girls a modern, equal education
11. Savsan is Tajik.
12. Sosamma is Malayalam, a language spoken in India.
13. Zsuzsanna is Hungarian.
14. Zuzanna is Polish and Latvian.
15. Zuzana is Czech and Slovak.
16. Huhana is Maori.
17. Zusana is Sorbian.
18. Syzana is Albanian.
19. Siùsan is Scottish.
20. Sósanna is a rare Irish form.
Polish poet Zuzanna Ginczanka, 1917–1945
21. Susaina is a Catalan variant, usually used on Mallorca.
22. Suzannah is English.
23. Suzonne is Norman.
24. Jujen is Marshallese.
25. Siwsan is Welsh.
26. Susane is English.
27. Suusan is Inuit.
28. Suzette is a French diminutive, also used in English as a full name.
29. Suzzanna is a rare English form.
30. Shushan is Armenian.
31. Susano is a male Filipino form.
Onomastics Outside the Box 
Wow, I didn’t realise it had so many different forms in non-Indoeuropean languages, though since its roots aren’t Indoeuropean it’s actually only to be expected so I don’t know why it surprises me so much, haha. Also didn’t know there was a male form.
I feel rather neutral about Susan(nah), but I do like our Polish Zuzanna quite a bit. The only thing that stops me from liking it even more is its overwhelming popularity. It was #1 for baby girls in 2019 over here and I don’t have earlier statistics at hand right now but I’m pretty sure it’s been in top 10 throughout the 21st century so far, so it does feel awfully overused, even among women born in the 90’s there are quite a lot of Zuzannas, whereas in slightly older generations this name feels nicely fresh and underused, albeit not totally rare. The most common nickname is Zuzia which I think is really nice, though naturally you’ll hear it a lot everywhere, my little sister (born in 2007) has three Zuzias among her school friends.