Gun Metal #360
 Dark  CC BY-SA 3.0

With a name this awesome, how can I go wrong?

Source Nikolay Boltachev

 More Textures
"Grunge-Like" Background Pattern #1126
 Grunge  CC BY-SA 3.0

Background pattern made in "Grunge-Like" style. Available in both SVG and JPG formats. Edit to your needs then click the download button.

Source V. Hartikainen

Background pattern 339 #1709
 Dark  CC 0

The tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i

Source Firkin

Floral Abstract Pattern Background #217
 Noise  CC 0

PDP

Source GDJ

Prismatic Groovy Concentric Background 5 #465
 Dark  CC 0

Prismatic Groovy Concentric Background 5

Source GDJ

My Little Plaid@2X #333
 Light  CC BY-SA 3.0

Repeating squares overlapping.

Source Pete Fecteau

Colourful background #2007
 Colorful  CC 0

Made by distorting a simple pattern using the 'sin waves' plugin for Paint.net and vectorising in Vector Magic

Source Firkin

Background pattern 339 (colour 2) #1707
 Green  CC 0

The tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i

Source Firkin

shell pattern #2533
 Brown  CC 0

The image depicts a shell seamless pattern.I used an OCAL clipart called "Shell" uploaded by "jgm104".Thanks.

Source Yamachem

Spotted Light Yellow BG Pattern #1216
 Yellow  CC BY-SA 3.0

This light yellow background pattern consists of an irregular pattern of spots. Here's a light background pattern with yellowish tint.

Source V. Hartikainen

Heart and rose pattern #2419
 Pink  CC 0

Seamless pattern formed from a square tile that can be retrieved in Inkscape by selecting the rectangle and using shift-alt-i.

Source Firkin

Background pattern 117 #524
 Noise  CC 0

A seamless pattern drawn originally in Paint.net by distorting a slice of background pattern 116 and copying the resulting triangle numerous times.

Source Firkin

Transparent Square Tiles@2X #299
 Grid  CC BY-SA 3.0

The first pattern on here using opacity. Try it on a site with a colored background, or even using mixed colors.

Source Nathan Spady

Ravenna #354
 Wall  CC BY-SA 3.0

I guess this is inspired by the city of Ravenna in Italy and its stone walls.

Source Sentel

Seamless Colorful Floral Pattern Background #256
 Fabric  CC 0

PDP

Source GDJ