Senior Abbreviation: How to Write Sr. the Right Way

Senior abbreviation after a name

The most common job for Sr. is to tell apart a father and son with the same full name. The father is Sr. and the son is Jr. A grandson with the same name is usually III, said "the third."

• Martin Diaz Sr. and Martin Diaz Jr.
• Mr. Martin Diaz Sr.
• Dear Mr. Diaz (the suffix is dropped in the greeting)

Older style put a comma before the suffix: Martin Diaz, Sr. Most current style guides leave the comma out, but either form is understood. If someone writes their own name with the comma, follow their choice. On forms with a separate "suffix" box, write Sr. there instead of in the last name field.

Abbreviation for senior in job titles

At work, Sr. marks a higher level in a job family: Sr. Accountant, Sr. Project Manager, Sr. Software Engineer. It usually means more experience and more responsibility than the base title, but less than a lead, principal or director role. Each company sets its own ladder.

• On business cards and email signatures: "Sr. Account Manager"
• In job postings: "Sr. Data Analyst, hybrid"
• In formal letters, many writers spell it out: "Senior Vice President"

The higher you go, the more often the word is written in full. A title like SVP, senior vice president, turns the word into one letter of an initialism. More office titles are on the CEO and HR pages.

Senior in school and class years

High schools and colleges sort students by year: freshman, sophomore, junior and senior. Rosters, yearbooks and team lists often shorten these.

A sports roster might read "Jordan Price, Sr., Guard." Here Sr. is the class year, not a family suffix. Campus rosters use plenty of other short forms too, collected in the school acronyms list.

Senior citizens and discounts

There is no official short form for senior citizen, but stores and transit systems often print "Sr." or "SR" on signs and receipts: "Sr. discount Tuesdays," "SR fare." In running text, write the full words. "Senior discount" reads better than "Sr. discount" in a sentence.

Groups for older adults, such as AARP, usually spell out the word too.

Sr. look alikes to watch for

• Sr. for Señor: in Spanish, Sr. means Mr. (Señor), and Sra. means Mrs. (Señora). "Sr. López" is a polite title, not a suffix.
• Sr. for Sister: in Catholic usage, Sr. Ann means Sister Ann, a nun.
• Sen.: short for Senator, not senior.
• SR in the Navy: the rank abbreviation for seaman recruit. Ranks have their own pages, like sergeant and captain.

Context sorts them out: a suffix comes after the last name, while a title comes before it.

Quick rules for writing Sr.

• Capitalize the S, lowercase the r, add a period in American English.
• Place it after the full name, not after a first name alone.
• Do not use it with Jr. on the same person.
• Use it only when the person uses it, or when two people share a name.
• Spell out "senior" in ordinary sentences.

For a full guide to shortening words, see how to abbreviate and the common abbreviations hub.