Looks like a technical drawing board: small squares forming a nice grid.
Source We Are Pixel8
I love these crisp, tiny, super subtle patterns.
Source Badhon Ebrahim
Tiny little flowers growing on your screen. Nice, huh?
Source Themes Tube
From a drawing in 'An Old Maid's Love. A Dutch tale told in English', Maarten Maartens, 1891.
Source Firkin
Alternative colour scheme for the original floral pattern.
Source Firkin
An alternative colour scheme to the original seamless pattern.
Source Firkin
From a drawing in 'Two Women in the Klondike', Mary Hitchcock, 1899.
Source Firkin
This is a seamless pattern which is derived from a flower petal image.
Source Yamachem
A cute x, if you need that sort of thing.
Source Juan Scrocchi
A background pattern inspired by designs seen in 'Burghley. The Life of William Cecil', William Charlton, 1857.
Source Firkin
I guess this one is inspired by an office. A dark office.
Source Andrés Rigo.
Seamless pattern the tile for which can be had by using shift-alt-I on the selected rectangle in Inkscape.
Source Firkin
A seamless pattern with a unit cell drawn as a bitmap in Paint.net and vectorized in Vector Magic.
Source Firkin
You know I’m a sucker for these. Well-crafted paper pattern.
Source Mihaela Hinayon
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Classic vertical lines, in all its subtlety.
Source Cody L
A background formed from an image of an old tile on the New York Metropolitan Museum of Art website. To get the base tile, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Might not be super subtle, but quite original in its form.
Source Alex Smith
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Not sure if this is related to the Nami you get in Google image search, but hey, it’s nice!
Source Dertig Media
You just can’t get enough of the fabric patterns, so here is one more for your collection.
Source Krisp Designs
Prismatic Curved Diamond Pattern No Background
Source GDJ
You may use it as is, or modify it as you like.
Source V. Hartikainen