The fashion of the 1920s, also known as the "Roaring Twenties," was marked by significant changes in both style and society, and was largely influenced by World War I (1914-1917). It was a time of economic growth and cultural transformation. Women gained the right to vote in several countries, and many of them who had taken jobs in male-dominated fields during the war continued in those jobs, appreciating the financial independence it provided. Society also experienced easy access to entertainment such as jazz music, cinema, and nightclubs. The fashion of the time reflected the cultural liberation taking place and showed a more relaxed attitude toward social norms. Women and workers gained more rights, leading to increased leisure time, and a growing interest in sports and leisure activities.The curving lines and natural details of the Art Nouveau style were replaced by the more streamlined and simple lines of the Art Deco style.

Women’s fashion in the 1920s represented a break from the more formal clothing of earlier eras. The flapper style, also known as “La Garçonne,” was particularly popular among younger women. This style was characterized by shorter dresses that ended around the knee and featured a low waistline, known as a "drop waist," that cut across the hips. The straight silhouette moved away from emphasizing traditional feminine curves, which had previously been accentuated by corsets. Short hairstyles like the bob, often styled with finger waves, were in vogue, and women started wearing more noticeable makeup—a stark contrast to earlier times when makeup was expected to be subtle. 

Dresses were often made from lightweight materials like silk, chiffon, and velvet, adorned with details like embroidery, sequins, and beads, especially for evening wear. Cloche hats became popular, directly inspired by the military helmets from World War I. They often had decorative bands or flowers and were worn low on the forehead.

Women’s shoes in the 1920s still featured the French heel, which had also been popular in the 1900s and 1910s. Mary Jane shoes, with a single strap across the instep, were very popular, and more attention was given to shoes and stockings now that dresses were shorter. Shoes were still mostly made from leather or satin, and came in a wide variety of colors. Red and cream-colored shoes became fashionable, and evening shoes were often found in metallic colors like gold and silver.

For men, the 1920s was a time of modernization, though the changes in style were not as dramatic as for women.

Most men wore some kind of a suit daily. Jackets and trousers became narrower, giving suits a more streamlined and elegant silhouette. The three-piece suit, consisting of a vest, trousers, and jacket, was common, and there was a wider use of striped suits. Clothing also reflected leisure activities, with specific outfits for driving, golfing, or skiing, which were more casual, often featuring knickerbockers, shirts with scarves, and straw hats or newspaper caps.

Oxford shoes or two-tone shoes—often black and white or brown and white—were popular among men. Leather lace-up boots in either brown or black, with a more rounded toe than previously, were also in style.

Sources: 

• Shoes - An Illustrated Story by Rebecca Shawcross
• Tidens Mode by Anne-Grete Steckhahn
• Vintage Fashion - Collecting and wearing designer classics by Emma Baxter-Wright, Karen Clarkson, Sarah Kennedy, and Kate Mulvey
• Vintage shoes - Caroline Cox