Mr. Xenomurphy's Superhero Contest 2013

Contest: Mr. Xenomurphy's Superhero Contest 2013
Hosted by: Mr. Xenomurphy, on MOCpages
Description/categories: The category for round 1 will be announced on July 12. Builders will have ~2 weeks. Highest scores will go on to round 2.
Deadline: Sign up before July 12 to enter the first round.
Contest rules

Write to Win contests

Contest: Write to Win
Hosted by: Legoland Discovery Centers
Description/categories: This one is just for the kids (sorry, AFOLs). I've linked the rules for the Legoland Discovery Center in Chicago, but they also have the same contest running at the Dallas/Fort Worth Legoland Discovery Center, so I'll assume the same contest is running at all of them (or at least all of them in the US). Kids 12 and under can win a family annual pass to the center for writing the best things to do in the Chicago area (or Dallas/Fort Worth, or presumably wherever any of the LDCs are), what makes a great birthday party, or five LEGO building tips. Winners will be chosen by votes on their Facebook pages. I don't see any residency requirement, so I'm guessing you could enter more than one of these (say, for example, you live in Oklahoma and could reasonably travel to both the Kansas City and Dallas centers).
Deadline: July 11
Contest rules (for the Chicago center)

Star Wars Contest

Contest: Star Wars Contest
Hosted by: Hothbricks, La Petit Brique, and Arealight
Description/categories: Create a SW themed vignette on a base with a total area of 256 studs (16x16 square, or rectangle with the same total number of studs)
Deadline: September 15
Contest rules

Voting: SW Randall LEGO Build Contest

Contest: Annual SW Randall LEGO Build Contest
Hosted by: S.W.Randall Toys (store in Pittsburgh, PA)
If you're in the Pittsburgh area, stop by the store to vote on your favorite MOC. Here's a news story on the contest.

Hero or Monster contest

Contest: Hero or Monster contest
Hosted by: Eurobricks
Description/categories: Based around the world of Hero Factory being invaded by alien parasites that turn Heroes and animals into monsters. Hero or Monster - build a Hero that has been mutated. Before and After Brain Infection - show an animal being transformed. Digital Hero - create your own Hero using CAD.
Deadline: July 9
Contest rules

Chima Contest/Raffle

Contest:
Hosted by: Eurobricks
Description/categories: Build a Chima MOC at Action Figure scale for a chance to win a drawing for signed Chima sets
Deadline: July 17
Contest rules

Brickmoc Minifig Contest

Contest: Brickmoc Minifig Contest
Hosted by: Brickmoc
Description/categories: Create a custom fig (any era) using Brickmoc products
Deadline: July 1
Contest rules

Time-Warp

Contest: Time-Warp
Hosted by: Friends Bricks forum
Description/categories: Design a Friends set you would have wanted as a kid.
Deadline: July 31
Contest rules

BBC Contest #65: For the Birds!

Contest: BBC Contest #65: For the Birds!
Hosted by: BZPower forum
Description/categories: Build a bird using Bionicle pieces. Entries will be on display at BrickFair Virginia (August 3-4), and attendees will vote on the winner.
Deadline: June 22 (sorry)
Contest rules

L13 20: The Great Painters

Contest: L13 20: The Great Painters
Hosted by: BrickPirate forum
Description/categories: Reproduce a famous painting in LEGO form.
Deadline: June 26 (yesterday, sorry)
Contest rules

L13 Contests

Contest: L13 Contests
Hosted by: BrickPirate LEGO forum
Description/categories: Each month the French language forum BrickPirate starts another contest, open to forum members. Look for new contests in the middle of each month, with 13 days to complete entries. Subjects vary widely from month to month.

Get to da chopper!

Contest: Get to da chopper!
Hosted by: BrickArms forum
Description/categories: Build a helicopter (any style, realistic or made-up, any scale) equipped with BrickArms products
Deadline: July 30
Contest rules

How it should have ended

Contest: How it should have ended
Hosted by: Flickr group
Description/categories: Illustrate an alternate ending for one of the six Star Wars movies.
Deadline: June 23 (sorry, I just saw this)
Contest rules

2013 Bio Cup

Contest: 2013 Bio Cup
Hosted by: MOCpages group
Description/categories: Technic/Bionicle/Hero Factory. This will be a single elimination tournament with different challenges for each head to head match-up.
Deadline: Sign up now. Round 1 will start on June 21.
Contest rules

BBW 2013

Contest: BBW 2013
Hosted by: LUGPol
Description/categories: This contest started earlier this year and involves six challenges. They are currently in stage 5.
Contest rules