Is there an eight dollar bill?

1) A very old form of Massachusetts currency included an $8 bill:

May 5, 1780 -- An emission of £394,000 ($1,313,333) in legal tender bills of credit payable in Spanish milled dollars with 5% interest by December 31, 1786. This issue was authorized pursuant to the Continental Congress Resolution of March 18, 1780. Printed by Hall and Sellers in Philadelphia using paper watermarked "United States." The front was printed in black with border cuts by Henry Dawkins. The back was printed in black and red with border cuts and emblems from the Continental Currency issue of January 14, 1779. The cuts surrounding the emblem are by Dawkins. Notes are sometimes surcharged in red "Interest paid one year" and usually hole canceled upon redemption. There are two signatures on the front and a guaranty signature on the back. Denominations issued were: $1, $2, $3, $4, $5, $7, $8 and $20.

link http://www.frbsf.org/currency/independence/original/s05.html


2) Benjamin Franklin apparently designed an eight dollar bill.

Other of Franklin's bills bore similar political themes. The eight-dollar bill depicted a harp whose thirteen strings represented the various colonies. The motto, Majora Minoribus Consonant, asserted that "the greater and smaller ones sound together." Franklin further explained that the harp’s frame, which united the strings "in the most perfect harmony," symbolized the Continental Congress. Several months later, he again sought to reinforce American unity, this time by portraying the colonies as a chain of thirteen links, which appeared on Congress's half-dollar bill and other fractional notes.

It doesn't appear to have ever gotten into circulation:

Franklin’s vision for U.S. money was decidedly republican: it incorporated neither kings nor coats of arms but rather celebrated selfless deeds and laudable persons. The Confederation Congress never followed through on its plans to establish a mint and so it could not adopt Franklin’s idea for a new coinage. But over the long course of U.S. history, Franklin’s numismatic vision came to prevail, making it possible for the image of a former runaway, an ex-apprentice, by virtue of his public service, to grace our hundred-dollar bill.

3) There are currently no 8 dollar bills in any of the world's currencies.

Links below for each world dollar:
https://en.wikipedia.org/wiki/US_Dollar
https://en.wikipedia.org/wiki/Canadian_dollar
https://en.wikipedia.org/wiki/East_Caribbean_dollar
https://en.wikipedia.org/wiki/Australian_dollar
https://en.wikipedia.org/wiki/Bahamian_dollar
https://en.wikipedia.org/wiki/Barbadian_dollar
https://en.wikipedia.org/wiki/Belize_dollar
https://en.wikipedia.org/wiki/Bermudian_dollar
https://en.wikipedia.org/wiki/Brunei_ringgit
https://en.wikipedia.org/wiki/Cayman_Islands_dollar
https://en.wikipedia.org/wiki/New_Zealand_dollar
https://en.wikipedia.org/wiki/Fijian_dollar
https://en.wikipedia.org/wiki/Guyanese_dollar
https://en.wikipedia.org/wiki/HKD
https://en.wikipedia.org/wiki/Jamaican_dollar
https://en.wikipedia.org/wiki/Liberian_dollar
https://en.wikipedia.org/wiki/Malaysian_ringgit
https://en.wikipedia.org/wiki/Singapore_dollar
https://en.wikipedia.org/wiki/New_Taiwan_dollar
https://en.wikipedia.org/wiki/Trinidad_and_Tobago_dollar
https://en.wikipedia.org/wiki/Zimbabwean_dollar

There used to be and a four and a six too

"Other of Franklin's bills bore similar political themes. The eight-dollar bill depicted a harp whose thirteen strings represented the various colonies. The motto, Majora Minoribus Consonant, asserted that "the greater and smaller ones sound together." Franklin further explained that the harp’s frame, which united the strings "in the most perfect harmony," symbolized the Continental Congress."


http://common-place.org/article/benjamin-franklins-enriching-virtues/