YA, yA, or Ya may refer to:

• Ya (arrow), the Japanese word for an arrow
• Ya (Cyrillic) (Я), a Cyrillic alphabet letter
• Ya (Javanese) (ꦪ), a letter in the Javanese script

• years ago (ya), a unit of time
• Yoctoampere (yA), an SI unit of electric current
• Yottampere (YA), an SI unit of electric current

• ¡Ya!, an album by the band Marquess
• Ya (film) [ru], a 2009 Russian sci-fi film with Artur Smolyaninov and Oksana Akinshina
• Yahoo! Answers (YA), a community-driven question-and-answer site
• Young Ace (YA), a Japanese magazine
• Young adult fiction, fiction marketed to young adults

• Ya (river), a river in Tynset municipality in Innlandet county, Norway
• Yet another (YA), a common initial part of acronyms
• YoungArts (YA), a scholarship program for American high school students
• A US Navy hull classification symbol: Ash barge (YA)

• Ya-ya (disambiguation)
• Yah (disambiguation)
• Yaya (disambiguation)
• Yea (disambiguation)
• Yeah (disambiguation)