It used to be the souther part of Hampshire County, but Hampden became a county in its own right in 1812. So when looking for older records, the towns currently in Hampden would have been in Hampshire County from 1662 until around 1812.
Getting Hampden County public records is fairly easy since they don't place any restrictions on who can request copies. But given the hundreds of years of history for the area, you will find there are several places where you may need to go for the records you need.
Recent material from today back until 1921 is held by the Registry of Vital Records and Statistics in Dorchester. You can visit in person for your request or mail in an application. The Office of Health and Human Services website has the proper form, which is used for several different kinds of records. Take care to fill out the right fields for the records you are seeking.
Farther back from 1921 but only until 1841, Hampden County public records move to the state's care and can be found at the State Archives in Boston. Unlike the Vital Records office, they don't just process requests on demand. You can either go to the research room and do some look-ups yourself or you can make some limited requests for staff to photocopy records for you, for a fee. Because these are public records, you can often find good indexes online through large genealogy websites.
Earlier than 1841 is not kept at any central location and you need to get in touch with the county clerk's office in Springfield to access old Hampden County public records from that age. Making a request from the county office will require the same forms as you would use with the state Vital Records registry.
Hampden County Birth Records
The cost to get a Hampden County birth record will depend on how you make your records request. A mailed-in order costs $28 and will take about a month to be processed and returned to you. If you go to the office in person, the fee is only $18 and you will get your certified papers while you wait. These fees only apply for either of the 2 government offices mentioned above. The State Archives do not have such fees.
Hampden County Death Records
When ordering a Hampden County death record, the fees will be the same as with the birth certificates. Getting a certified copy of a death certificate just requires that you have the name, date and location of death of the person on the record.
Hampden County Marriage Records
Hampden County marriage records work the same as birth and death records, and can be accessed via the same sources. The cost for each requested copy is also the same.
Hampden County Criminal Records
The county doesn't regulate criminal files, so you will have to apply to the Department of Criminal Justice Information Services in order to get copies of Hampden County criminal records. Their website has further instructions and the fee for each record is $30. You can always order a copy of your own background file, but other records may be classed as private depending on their crime and sentence.