In the U.S., the Patent Act provides that a “patentee” is entitled to bring a civil action for infringement of his/her patent. This has been interpreted to cover the individual inventor(s) to whom the patent was issued as well as the inventor’s heirs or other successors in title. Alternatively, if the patentee conveys “all substantial rights” in the patent to a third party (such as an employer), the third party is treated as the patentee and has standing to sue in its own name.” This is the typical case where an assignee/employer sues on behalf of an inventor/employee. There is no “right to sue” for infringement separate from a conveyance of a proprietary interest in the patent.
Under the newly acted provisions of the AIA, since a non-inventor can now apply for a patent, I believe such a party would also have standing to sue for infringement, but I can’t say for certain off the top of my head.

So the party that “owns” a patent can commence an action for patent infringement, however, a licensee ordinarily cannot, unless the license exclusively grants “all substantial rights” in the patent (i.e. a license the that is virtually equivalent to an assignment). In some circumstances, an exclusive license that grants something less than “all substantial rights” can permit the licensee to join the patentee in suing an infringer, but the licensee couldn’t bring suit on its own. A “bare licensee,” that is, someone who merely has non-exclusive permission to exercise one of the rights granted by a patent, doesn’t have standing to sue third parties for infringement, even if the patentee wants them too.

I disagree with the answer above to the extent it implies that a licensed distributor or retailer could bring a suit for patent infringement in the case that the patentee does not. They certainly might have a complaint against the patentee, depending on the terms of the license, but they would have no basis to sue the alleged infringer.

In the U.S., the Patent Act provides that a “patentee” is entitled to bring a civil action for infringement of his/her patent. This has been interpreted to cover the individual inventor(s) to whom the patent was issued as well as the inventor’s heirs or other successors in title. Alternatively, if the patentee conveys “all substantial rights” in the patent to a third party (such as an employer), the third party is treated as the patentee and has standing to sue in its own name.” This is the typical case where an assignee/employer sues on behalf of an inventor/employee. There is no “right to sue” for infringement separate from a conveyance of a proprietary interest in the patent.

Under the newly acted provisions of the AIA, since a non-inventor can now apply for a patent, I believe such a party would also have standing to sue for infringement, but I can’t say for certain off the top of my head.

So the party that “owns” a patent can commence an action for patent infringement, however, a licensee ordinarily cannot, unless the license exclusively grants “all substantial rights” in the patent (i.e. a license that is virtually equivalent to an assignment). In some circumstances, an exclusive license that grants something less than “all substantial rights” can permit the licensee to join the patentee in suing an infringer, but the licensee couldn’t bring suit on its own. A “bare licensee,” that is, someone who merely has non-exclusive permission to exercise one of the rights granted by a patent, doesn’t have standing to sue third parties for infringement, even if the patentee wants them too.

I disagree with the answer above to the extent it implies that a licensed distributor or retailer could bring a suit for patent infringement in the case that the patentee does not. They certainly might have a complaint against the patentee, depending on the terms of the license, but they would have no basis to sue the alleged infringer.