Suit jacket in the context of "Classic menswear"

A suit, also called a lounge suit, business suit, dress suit, or formal suit, is a set of clothes comprising a suit jacket and trousers of identical textiles generally worn with a collared dress shirt, necktie, and dress shoes. A skirt suit is similar, but with a matching pencil skirt instead of trousers. It is currently considered semi-formal wear or business wear in contemporary Western dress codes; however, when the suit was originally developed it was considered an informal or more casual option compared to the prevailing clothing standards of aristocrats and businessmen. The lounge suit originated in 19th-century Britain as sportswear and British country clothing, which is why it was seen as more casual than citywear at that time, with the roots of the suit coming from early modern Western Europe formal court or military clothes. After replacing the black frock coat in the early 20th century as regular daywear, a sober one-coloured suit became known as a lounge suit.

Suits are offered in different designs and constructions. Cut and cloth, whether two- or three-piece, single- or double-breasted, vary, in addition to various accessories. A two-piece suit has a jacket and trousers; a three-piece suit adds a waistcoat. Hats were almost always worn outdoors (and sometimes indoors) with all men's clothes until the counterculture of the 1960s in Western culture. Informal suits have been traditionally worn with a fedora, a trilby, or a flat cap. Other accessories include handkerchief, suspenders or belt, watch, and jewelry.

A necktie (American English) – also called a long tie or, more usually, simply a tie (Commonwealth English) – is a cloth article of formal neckwear or office attire worn for decorative or symbolic purposes, knotted at the throat, resting under a folded shirt collar, and usually draped down the chest. On rare occasions neckties are worn above a winged shirt collar. Neckties are usually paired with collared dress shirts under suit jackets or blazers, but have often been seen with other articles, such as sport coats and v-neck sweaters. Neckties can also be part of a uniform, however, in occupations where manual labor is involved, the end of the necktie is often tucked into the button line front placket of a dress shirt, such as the dress uniform of the United States Marine Corps.

Neckties are reported by fashion historians to be descended from the Regency era double-ended cravat. Adult neckties are generally unsized and tapered along the length, but may be available in a longer sizes for taller people, designed to show just the wide end. Widths are usually matched to the width of a suit jacket lapel. Neckties are traditionally worn with the top shirt button fastened, and the tie knot resting between the collar points. Importance is given to the styling of the knot. In the late 1990s, Thomas Fink and Yong Mao of University of Cambridge mathematically determined 13 knots as "aesthetically" viable out of a possible total of 85, of which the commonest known are the four-in-hand, the Pratt, and the Windsor knots. The cut of the folded collar of the dress shirt is typically paired to the style of knot used. Neckties were originally considered "menswear", but are now considered unisex items in most Western cultures.

A blazer is a distinct type of lightweight sports jacket, traditionally made of navy or striped wool or linen. It is typically characterised by metal buttons on the front and sleeves. In terms of formality within Western dress codes, a blazer has a dressier appearance than other sports jackets, yet is seen as less formal than a suit jacket.

First introduced in the 1860s as a scarlet jacket in club or plain colours for boating or cricket, it began to shed its sporting associations in the 1930s. The double-breasted navy version in particular established itself as a staple of classic style, occupying a space between the casual tweed jacket and the formal dark suit, and soon became linked to the lifestyle of wealthy elites. Coloured variants, however, continue to appear in some circles as semi-active sportswear, notably after cricket or rowing.