Background pattern 306 (colour 2) #1881
 Colorful  CC 0

Seamless pattern the tile for which can be had by using shift-alt-I on the selected rectangle in Inkscape.

Source Firkin

 More Textures
Soft Wallpaper #95
 Wall  CC BY-SA 3.0

Coming in at 666x666px, this is an evil big pattern, but nice and soft at the same time.

Source Atle Mo

Background pattern brown #1945
 Brown  CC 0

To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.

Source Firkin

Background pattern brown #1951
 Brown  CC 0

To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.

Source Firkin

Prismatic Groovy Concentric Background 5 #465
 Dark  CC 0

Prismatic Groovy Concentric Background 5

Source GDJ

Background pattern 290 #1932
 Dark  CC 0

To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.

Source Firkin

Sakura Blossoms Background #389
 Noise  CC 0

Sakura Blossoms Background

Source GDJ

Background pattern 224 (colour 2) #2341
 Colorful  CC 0

To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.

Source Firkin

Street Art Pattern #1196
 Concrete  CC BY-SA 3.0

Looks as if it's spray painted on the wall. You can be sure that this pattern will seamlessly fill your backgrounds on web pages.

Source V. Hartikainen

Lego background #266
 Noise  CC 0

Background formed from the iconic plastic construction bricks that gave me endless hours of fun when I was a lad.

Source Firkin

Background pattern 261 #2076
 Dark  CC 0

Inspired by a pattern found in 'A General History of Hampshire, or the County of Southampton, including the Isle of Wight', Bernard Woodwood, 1861

Source Firkin

Graphy #350
 Grid  CC BY-SA 3.0

Looks like a technical drawing board: small squares forming a nice grid.

Source We Are Pixel8

Prismatic Geometric Tessellation Pattern 3 No Background@2X #556
 Noise  CC 0

Prismatic Geometric Tessellation Pattern 3 No Background

Source GDJ