Year 197 BC was a year of the pre-Julian Roman calendar. At the time it was known as the Year of the Consulship of Cethegus and Rufus (or, less frequently, year 557 Ab urbe condita). The denomination 197 BC for this year has been used since the early medieval period, when the Anno Dominicalendar era became the prevalent method in Europe for naming years.
The Spartan ruler, Nabis, acquires the important city of Argos from Philip V of Macedon, as the price of his alliance with the Macedonians. Nabis then defects to the Romans in the expectation of being able to hold on to his conquest.
The Battle of Cynoscephalae in Thessaly gives a Roman army under pro-consul Titus Quinctius Flamininus a decisive victory over Philip V of Macedon. In the Treaty of Tempe, the terms of the peace proposed by the Roman general and adopted by the Roman Senate specify that Philip V can retain his throne and control of Macedonia, but he has to abandon all the Greek cities he has conquered. Philip also has to provide to the Romans 1,000 talents as indemnity, surrender most of his fleet and provide hostages, including his younger son, Demetrius, who are to be held in Rome. The Aetolians propose that Philip V be ejected from his throne but Flamininus opposes this.