Can a married couple be given separate gift checks of $15000 from the same person and not have it count as income on their 2018 returns? Is there any penalty for the giver?
Assuming US since question uses the annual gift tax exclusion rate for US.
The annual gift tax exclusion is per person giving to another person. So a parent could give 2x to couple by giving to husband and wife, or a couple could give 4x to another couple. There is no filing requirement created if the gift amount is under the annual exclusion.
If gifts exceed the annual exclusion amount (or if gifts are given by each spouse), the giver has a filing requirement, not the recipient (it's not reported as income on the recipients return). The giver files Form 709 with their return, but they won't actually owe gift tax unless they have exhausted their lifetime exemption ($11.2 million, or double for couples if planned properly).
In the U.S., with the facts stated, there is no need for the giver or recipients to file a gift tax return.