Having a criminal record does not necessarily mean you will not be allowed to travel, but convictions may be grounds for refusal to grant a visa, entry or passport application. Unless otherwise specified, a criminal record does not prohibit you from travelling domestically, but can create problems when travelling internationally.
Obtain a passport. A criminal record should not affect your passport application, unless you are currently have outstanding arrest warrants, have a court order restricting your travel or bail conditions which specify that you stay in a certain area. Even in these situations, it may be possible to get a passport or have international travel approved by a court.
Each country has different rules and policies about allowing entry to travellers with criminal records. When planning a trip, it is important to check with the embassy or consulate of the country you wish to visit. You are not obligated to give your name or any contact information when enquiring with the country's embassy.
Some countries, such as the United States, require travellers with criminal records to get a waiver, which is a matter of a fee and an application. In the U.S., this good for five years, but validation varies by country. Other countries have no restrictions to criminal records, while some deny entry to only those convicted of specific crimes, such as murder, or anything having to do with guns or drugs.
Most visa applications will ask about any convictions and their nature. A criminal record does not necessarily mean your visa application will be denied.
If you are on bail or facing charges, check with the proper authorities about your travel restrictions.
If you break a law in country that you have entered illegally (even something as small as speeding), then you can be charged with illegal entry if you did not declare a previous criminal record at customs.
With the amount of people that go through customs every day, it would be impossible to check the criminal background of each traveller. However, the country you are entering will be able to use your information (name, passport number or finger prints) to pull up your criminal record through the CPIC system, if they choose to do so.
If you were pardoned in your country, this is not internationally recognised, so your criminal record in the system may not show the pardon.